VERPS: A VERB EXERCISEAND REFERENCE PROGRAM WITH SPEECH

FOR ARABIC LANGUAGE INSTRUCTION

by

ARVIN LEVINE,t

Institute for Mathematical Studiesin the Social SciencesStanford University

HAS MIG SEROPIAN

Institute for Mathematical Studiesin the Social SciencesStanford University

LAWRENCE Z. MARKOS IAN

Institute for Mathematical Studiesin the Social SciencesStanford University

CHARLES FERGUSON

Department of LinguisticsStanford University

As PART of a long-range goal to develop a language-instruction programfor Arabic, a project to achieve a computerized VERPS, Verb Exercise andReference Program with Speech, has been developed. The goal of theproject was to develop a system for utilizing high-quality computer­synthesized speech for teaching Arabic verbs, and to use this speech systemas part of a drill and reference program for these verbs. Work was done onthe three aspects of the project: verb selection and recording of basic forms,construction of the drill and practice program, and development of com­puterized audio synthesis of verb forms given prefix, stem, and suffixinformation.

VERPS can be used to generate the sounds and printed tokens (using astandard transcription, adapted for a computer terminal; see Appendix A)for a large numberofcommon verbs in Modern Standard Arabic (MSA) froma relatively small data base. It can also be used to present interactive drillexercises for students, with exercises presented on video-display terminals,accompanied by high-quality computer-synthesized speech. In addition,VERPS is usable as a reference source for information on Arabic verbs,including pronunciation, for both students and researchers.

Potential uses of the VERPS system are many; we list here the mostobvious:

1. VERPS can be used by students to drill Arabic verb forms.

2. Using VERPS, an instructor easily will be able to assign virtually limitlesskinds of Arabic verb drills for his students.

tNowat Four-Phase Systems, Cupertino, Calif.

The reasearch reported in this article was partially supported by the U.S. Office of Educa­tion, ISBjDIE, Grant G-007901815.

735

736 A. LEVINE, MARKOSIAN, SEROPIAN & FERGUSON

3. VERPS can be used by students and researchers to obtain the stem and pro­nunciation of verb forms encountered in MSA texts.

4. The VERPS system can be used as a dictionary of spelling, pronunciation,and morphology for Arabic verbs.

We expect an extension of the VERPS system to be used as part of Arabiccourses taught at Stanford, However, the principal value of the project wasin the development and demonstration of techniques which can be usedfor teaching Arabic and other language courses. In this regard a key ele­ment of VERPS was an extension of the Institute's existing system ofcomputer-synthesized speech (see Sanders & Levine, 1981) to generatethe sounds for Arabic verb forms from a systematic transformation ofthe sounds for verb stems and affixes. Any language course using computer­synthesized speech requires this capability since it is infeasible to storethe sounds for each of the many forms of every verb (or words from otherinflected grammatical classes) in a highly inflected language.

We selected Arabic because it presents, in its complex morphology, mostof the typical difficulties in the way of successful speech synthesis. Also,although not one of the most commonly taught languages in this country,Arabic is a major world language and is only second to the most commonlytaught foreign languages.

1. THE SYSTEM OF THE ARABIC VERB

Arabic verb forms are complex but regular. More than one hundred(109) grammatical categories are needed to describe all the different forms,although hardly any verb has that many distinct lexicographic forms. Atypical verb (e.g., Iwtaba, "to write") has 79 distinct lexicographic forms.There are fewer distinct forms than categories since different categoriesmay be expressed by the same lexicographic form. For verbs that do nothave a passive voice, the number of distinct forms is reduced to 42. Therelationships of some of the different forms are displayed in the tree struc­tures of Figure 1.

In addition to the category combinations expressed by a path through adependency tree, each verb form also expresses person and gender. (Theset of abbreviations we use for the tenses, persons, and genders is given inAppendix A.) Except for the Active-Imperative, every path (e.g" Active­Perfect, Passive-Imperfect-Indicative) can have three persons (1st, 2nd,3rd), three numbers (singular, plural, dual, abbreviated sg, pI, and dl) andtwo genders (masculine and feminine, abbreviated m and f), Certainlogically possible combinations are not expressed in MSA:

1. lst-m-sg, lst-f-sg, lst-m-pI, and lst-f-pI; because the gender of 1st personverbs is not identified.

ACliIVE, I ,

, I '/ I \

, I ,, I ,

, I 'II I \

Perfect : ImperativeII

Imperfect, ,, ,, ,, ,,/" "," ,Indicative Subjective

Jussive

ARABIC

PASSIVE, ,, ,, ,, ,, ,, ,, ,, ,Perfect lrIJperfe\ct

, ,, ,, ,, ,, ,, ,, ,Indicative Subj~nctive

Jussive

737

Figure 1. Tree structure dependencies of MSA verb system.

2. 1st-m-clI, lst-f-dl; because the dual is only expressed with the second andthird persons.

3. 2nd-m-dl, 2nd-f-dl; because gender is not expressed with the 2nd persondual. The 2nd-dual has no m or f (only 2nd-dl).

For the Active-Imperative path, the only combinations expressed are:2-m-sg, 2-f-sg, 2-dl, 2-m-pl, 2-f-pl; all others are excluded.

In addition to the inflectional system, Arabic verb morphology also hasa derivational system in which the three-consonantal root is used to deriveseveral other verbs with new meanings. Thus, from naZara, "he saw", isderived /intaZara, "he awaited"; from sa/ala, "he asked", is derived tasaa/ala,"he inquired". These derived verbs and their conjug<.ltions are also in­cluded in our program, but the derivation ofnew verbs from three-consonantroots is not included (see Cowan, 1958).

1.1 Inflectional System of MSA Verbs

The verb in Arabic, as in other Semitic languages, uses not only affixa­tion but also changes in the vowels between root consonants to indicatenumber, gender, person, tense, mood, and aspect. Thus, a basic verb withthree root consonants can have vowel insertions as follows in addition toprefixes and suffixes:

k-t-b: "to write"

Active:Imperative:Passive:

Perfect

katabktubkutib

Imperfect(Indicative)

ktub

ktab

Affixation on this root has the pattern shown below. The affixes accom­panying the Passive voice are identical with those for the Active except forthe Imperfect prefix. In the Passive Imperfect, the "a" vowel occurring in

738 A. LEVINE, MARKOSIAN, SEROPIAN & FERGUSON

Active Imperfect prefixes is changed to "u". As mentioned above, there isno Passive Imperative. While not shown in the table, the Imperfect canalso have Subjunctive and Jussive forms.

Active/Passive Active (Passive)Perfect Imperfect

Suffix Prefix Suffix

1 sg -tu la-(lu- ) -u2 sg m -ta ta-(tu-) -u2 sg f -ti ta-(tu-) -iina3 sg m -a ya-(yu-) -u3 sg f -at ta-(tu-) -u2 dual -tumaa ta-(tu-) -aani3 dl m -aa ya-(yu-) -aani3 dl f -ataa ta-(tu-) -aam1 pi -naa na-(nu-) -u2 pi m -tum ta-(tu-) -tiuna2 pI f -tunna ta-(tu-) -na3 pI m -uu ya-(yu-) -iluna3 pI f -na ya-(yu-) -na

ActiveImperative

Prefix Suffix

lu-Ju- -ll

/u- -aa

/u- -Ull

/u- -na

Stem changes combine with the prefixing and suffixing rules to producethe different verb conjugations. We continue, below, the example of k-t-b,"to write". On the far right of the table, we give one example of each tense.The stem is italicized in each example and all examples are given in thethird person masculine singular except for the Imperative which is in thesecond person masculine singular. The schematic rules for the stem changesare presented in the center column. "e" means some stem consonant and"a" and "u" are the vowels inserted into the stem. Suffixes are sometimesnull, as in the imperative form, luktub.

Conjugation

Active PerfectActive imperfectPassive perfectPassive imperfectImperativeActive participlePassive participle

schematic rule

CaCaC-suffixprefix-aCCuC-suffix

CuCiC-suffixprefix-Cae-suffixprefix-CCuC-suffix

CaaCiCprefix-CCuuC

examples

katabayaktubukutibayuktabuluktubkaatibmaktuub

The above example is only one conjugational pattern in one verb type. traditionally identified as Type I or Form I and which we refer to as Con­jugation 1. There are ten conjugations generally identified in MSA (see Ab­boud et aI., 1975). Within Conjugation I there are several vowel alternationpatterns. Other conjugations follow similar, regular patterns of conjugation.

A summary of the conjugational patterns for all the ten conjugations ofMSA is given in Figure 2 and a summary of the affixes occurring in all

ARABIC 739

patterns is in Figure 3. In Figure 2 when the prefixes are identical to thosein another conjugation we give the conjugation number (in Roman nu­merals) rather than list the prefixes. The affix 0 indicates a null addition(both phonetically and orthographically) to the stem. From these figures itis clear that the phone~ic material for the entire affixing system is quitelimited, but the rule for assigning a particular affix to a particular form ofa given verb is quite complicated.

Conjugation I II III IV V VI VII VIII IX Xac-pf 0 I I la- I I ji- VII VII VIIac-ipf la- lu- II II I I I I I I

ta- tu-ya- yu-na- nu-

ac-imp li- 0 II II II II ji- VII VII VIIlu-

ps-pf 0 lu- VII N VIIps-ipf lu- I I 0 I

tu- Nyu- Enu-

Figure 3. Summary of all prefixes and affixes applicable to MSA verbs.

Prefixes (9):la- ta- ya- na- lu- /i- tu- yu- nu-

Suffixes(l9, including 0):-til -ta -ti -a -at -tumaa -aa -ataa -naa -tum -tunna-uu -na -u -iina -aani -iluna -ii -0

Figui'e 2. Summary of prefixes applicable to MSA verb forms.

In addition to the verb's Conjugation number, stem information (suchas that given above for k-t-b) must be listed for each verb. A summary ofthis information is given in Figure 4. Some verbs have no passive; this wasalso listed for those verbs.

Once the lists and patterns are thus set up for individual verbs, we haveconcentrated on matching prefixes and· suffixes with each other and withthe right form of the stem. We discuss the use of these patterns in our drillprogram in section 2.

We have included a variety of patterns in conjugation I verbs (and allthe other verb conjugations). In addition to the "sound verbe" (e.g., kataba,"he wrote") and "doubled (geminate) verbs" (e.g., dalla, "he indicated"),we also have "defective (weak) verbs" (e.g., daama, "it lasted" and sa/ala,"he asked"). See section 1.3 for a fuller discussion of verb selection andAppendix B for a complete list of the verbs selected.

740 A. LEVINE, MARKOS IAN, SEROPIAN & FERGUSON

AC, PF AC,IPF IMP PS,PF PS,IPF

·CACCAC·

·CCAC··CCAC··CCAC··CCAC··CCAC·

CUCCIC·

CUCIC·CUCIC·CUCIC·CUCIC·CUCIC·

CACCIC·

A. Conjugation 1: Vowel reduction in first syllable.1. A·AA CACAC· ·CCAC· ·CCAC·2. A·U·A CACAC· ·CCUC· ·CCUC·3. A·I·A CACAC· ·CCIC· ·CCIC·4. I·A·A CACIC· ·CCAC· ·CCAC·5. U·U·A CACUC· ·CCUC· ·CCUC·

B. Conjugation II: No vowel reductionA·I·A CACCAC· ·CACCIC·

C. Conjugation III: No vowel reductionA·I·A CAACAC· ·CAACIC· CAACIC· CUUCIC· ·CAACAC·

D. Conjugation IV: No vowel reduction, prefix required for PerfectA·I·A ·CCAC· ·CCIC· ·CCIC· ·CCIC· ·CCAC·

E. Conjugation V: No vowel reduction, prefix required for .PerfectA·A·A ·CACCAC· ·CACCAC· ·CACCAC· ·CUCCIC· ·CACCAC·

F. Conjugation VI: No vowel reduction, prefix required for PerfectA·A·A ·CAACAC· ·CAACAC· ·CAACAC· ·CUUCIC· ·CAACAC·

G. Conjugation VII: No vowel reduction, prefix required for PerfectA·I·A ·NCACAC· ·NCACIC· :NCACIC· ·NCUCIC· ·NCACAC·

H. Conjugation VIII: No vowel reduction, prefix required for PerfectA·I·A ·CTACAC· ·CTACIC· ·CTACIC· ·CTUCIC· ·CTACAC·

I. Conjugation IX: No vowel reduction, prefix required for Perfect, no PassiveA-A -CCACC- -CCACC- -CCACIC- no passive

J Conjugation X: No vowel reduction, prefix required for PerfectA·I·A ·STACCAC· ·STACCMIC· ·STACCIC· ·STUCCIC· ·STACCAC·

Figure 4. Summary of inflectional information of Arabic verb stems by conjugation.

1.2 Selection of Verbs

Two sources were used in the selection of verbs to be included in thisproject: R. Scheindlin, 201 Arabic Verbs and P. Abboud et aI., ElementaryModern Standard Arabic. Scheindlin's book selects its verbs from M. Brill'sWord List of the Arabic Daily Newspaper. The verbs there are selected, asScheindlin states, "with a view to provir-ing as complete coverage as possibleof weak verb patterns". This goal, of complete pattern coverage, was also aconsideration in our selections, but in order to ensure the program'susefulness to existing programs for teaching Standard Arabic, we consultedone of the more commonly used textbooks of Modern Arabic, that of Ab·baud and his colleagues. The example verbs in this textbook were con·sidered first and were usually included in order to include the most fre­quently used verbs. The Scheindlin book was also used as a source forspecifying all the forms of a particular verb.

A file of ninety verbs (with summary descriptions of all their forms)was created. These ninety verbs cover all ten verb types of StandardArabic and include verbs in the so·called defective (or weak) verb cate·gories. Our list of verbs to be used in the drills is comprehensive in itscoverage of all verb types. The forms for these ninety verbs and the rulesfor prefixing and suffixing them, constitute the input to the drill program

ARABIC 741

we have developed as part of the current project. The verbs we have chosenare listed in Appendix B. We have recorded at least one exemplar of eachverb for the audio part of this project. The list of recorded examples, withtheir grammatical categorization, is given in Appendix C.

2. PRINCIPAL COMPONENTS OFTHE DRILL AND PRACTICE PROGRAM

Arabic verb drills are conducted on the Institute's standard video­display terminals, using a Roman transliteration (see Appendix A) for theArabic alphabet. The system of computer-synthesized speech has been in­corporated in a general way into the drill program. The principal compo­nents of the drill program are: output grammar, input grammar, drill generator,and speech synthesizer. The first three components are discussed in thissection. A transcript showing many of the features of the output and inputgrammars is included in Appendix D. The speech component is morefully discussed in section 3.

2. I Output Grammar

The output grammar generates the lexical representation of the verb­form specified. Input to the program is specification of a verb-form (e.g.,ps-ipf-sbj-3-m-sg) and a verb stem, which can be specified by its consonantsalone (e.g., f91) or in other ways. The output grammar looks up the verbstem in a file of known stems in order to obtain 'verb-dependent informa­tion, including conjugation, stem form (vowel placement and elision),imperative prefix (for first conjugation verbs), gloss, and (optionally) apointer to a file containing irregular forms. The next step in generatingthe lexical representation is to select the prefix and suffix; in general; theseare functions of the conjugation and form specification. For irregularforms, and for the imperative prefix of first conjugation verbs, they arealso a function of the verb stem. Finally, the stem form itself (reflectingchoice of vowels, and dependent on conjugation and form specification)is determined.

An important feature of the output grammar is that it requires, at most,the specification of four parameters for each regular verb stem (verb stem,conjugation, stem form, and imperative prefix) to construct the vast major­ity of "regular" verbs. Thus it is easy to add new regular verbs to the set ofstems that the program can accommodate. In addition, irregular forms forany verb can be specified readily to the program.

The output grammar not only provides an orthographic representationof the specified verb form, but it also provides the input to the speech­generation program. For this purpose, the output grammar must keep theprefix, stem, and suffix separated for the speech component.

742 A. LEVINE, MARKOS IAN, SEROPIAN & FERGUSON

2.2 Input Grammar

The input grammar works in the reverse method from the output gram­mar: it determines, from an orthographic input (token), the verb stem andgrammatical form(s) represented. In general there may be several gramma­tical forms represented by the same token. Thus, for example, the inputgrammar will determine that the token tuj9alaa can represent any of thefollowing forms:

ps-ipfCsbj-2-dl,ps-ipfCsbj-3-f-dl,

ps-ipf-js-2-dl,ps-ipf-js-3-f-dl.

Tokens which do not represent valid forms (for example, a conjugationmismatch between stem and prefix, or simply an incorrect prefix or suffix)are detected as invalid, as explained below.

The input grammar begins by extracting (isolating) the prefix andsuffix, if any, and then the stem. More precisely, a finite-state automatonparses the token for possible prefixes and suffixes. In most cases, there areonly three possibilities for each. Then each possible pairing is consideredand the root candidate corresponding to each is extracted. The lookup ofthe root (i.e., the stem from which vowels have been extracted) in a tableof roots uniquely determines the correct analysis, or parsing, into prefix­stem-suffix. It should be noted that by this point no judgment has beenmade on the legality of the combination of prefix, stem, and suffix (i.e., nosemantic analysis has been done).

Finally, the list of possible-form specifications corresponding to prefix,stem, and suffix are compared; the intersection of these lists is the set offorms represented by the token. The lists themselves are functions of stemconjugation and prefix and suffix tokens.

The two-stage analysis of the token allows the input grammar to detectprefix-stern-suffix mismatches as such; this kind of error is distinguishedfrom a spelling error which results in an incorrect prefix, stem or suffix.In a pedagogical application, it is important that the input grammar (aswell as the other components of the program) not merely reject studentinput as "invalid", but attempt to analyze incorrect input and explain thenature of the error. For an extension of the input grammar in an actualteaching .application, systematic error detection could be elaborated evenfurther.

As with the output grammar, the files used by the input grammar areeasily extended to accommodate a: new verb stem if it is conjugated in thesame way as any of the verb stems already in the file.

2.3 Drill Program

The drill program utilizes the input and output grammars to allow thegeneration of simple Arabic verb drills. The drill types available, pre­sented in Figure 5, are characterized by a stimulus generated by the program

(verb-form)

(verb-form)

(verb-form)(form-specification>(verb-form)

ARABIC 743

Stimulus Response

1. Type the verbcforrn you hear:(spoken verb form)

2. Specify form of (spoken & typed verb-form):3. Change (verb-form) to (form-specification):4. Type the verb (form-specification) for

the Arabic stem (stem):5. Type the correct form of (typed verb form)

corresponding to the pronoun (pronoun):

Figure 5. Summary of VERPS drill types.

and a response required of the student. The stimulus may consist of a typedmessage and/or a spoken cue; the response is always typed. In this figure,terms contained in brackets « and» represent general descriptions whichthe program replaces by the appropriate tokens.

Currently, the student selects the verbs which he wants to drill. Forpedagogical use, the system should be extended to allow the curriculumauthor (instructor) to specify classes of verbs and forms to be drilled atdifferent course levels.

The Arabic verb system was of sufficient interest and complexity byitself that the drill program was limited to verb drills. The verb drill gen­erator lends itself to further extensions, such as combining verbs into morecomplex constructions, using pattern drills and replacing the fairly abstractform specification by the use of appropriate pronouns and glosses.

The input grammar was originally written in a dialect of the LISP pro­gramming language called Standard LISP since this programming languageis well-suited to symbol manipulation. It was then rewritten in TENEX­SAIL (a high-level programming language for the PDP-1O computer) andSAlLISP (an extension to SAIL which contains a simulation of a subset ofLISP); it was then combined with the output grammar and drill generator,which were written in TENEX-SAIL in order to maintain compatibilitywith the audio program. The programs currently run only on the Institute'sPDP-1O computer running under the TENEX operating system. The non­audio parts of the program (grammars and drill generator) could be adaptedto run on any DEC-20 or PDP-1O computer.

The audio system which generates the computer-synthesized speechconsists of a group of hardware and software modules and is available onlyat the Institute. Currently there is no plan to duplicate the audio systemelsewhere.

The VERPS system is available for demonstrations at the Institute.

2.4 Uses of the Program

Supplement to traditional instructional methods. By itself, this pro­gram can be used in a supplementary way to reinforce what is alreadylearned in the classroom and to introduce a much larger number of verbs

744 A. LEVINE, MARKOS IAN, SEROPIAN & FERGUSON

than is possible in the classroom. In addition, the system can be used as areference for Arabic verb forms; currently there is no SOUTce in which allthe lexicographic forms for many verbs are printed. More importantly,however, it can become a starting point for a more extensive Arabic pro­gram where the student can learn to build sentences around these verbsand learn the variations across dialects.

Reference for word stem identification. Another important applicationof the program is for students who wish to look up a word encountered intext material: the student may simply enter the form of the word as itappears, and the program is able to specify the stem or other informationwhich can then be used to look up the word in a dictionary. This us-e as areference is particularly attractive in learning a language like Arabic sinceit takes the beginner a long time to acquire the necessary ease in recog­nizing what these stems are.

Specification of complete morphology given word stem. The useful­ness of VERPS is not limited to the beginning student. We anticipate thatVERPS will also be extremely valuable to authors and teachers who mayneed the conjugation of verbs they have not encountered before. In addi­tion, VERPS can be of immense help to textbook authors who often needlong lists of verb forms and extensive cross-referencing for their examples;dictionaries and grammars fail to address either of these needs since theylist only selected conjugational forms.

3. AUDIO SYNTHESIS OF ARABIC VERB FORMS

An important part of the work done for this project was the developmentof a capability to produce, using high quality computer-synthesized speech,the verbal forms to be presented. The Micro-programmed Intoned SpeechSynthesis (MISS; see Sanders & Levine, 1981) system using Linear Pre­diction (LP) coding provided the general capability for high quality speech.We have developed the MISS capability into two modes of presentation forthe verbal forms of Arabic. One mode uses the simple analysis and re­synthesis of recorded verbs. In this mode, a large number of verb formswere recorded, digitized, analyzed, and stored on random-access disk forrapid retrieval and resynthesis through the MISS synthesizer. For theimplementation of this mode, we recorded at least one exemplar of theninety MSA verbs that were selected, as well as the complete conjugationparadigm for one verb (lakala, "to eat"), and parts of the paradigms forten other verbs, chosen to represent different phonetic environments

'created by MSA verb conjugation. A complete list of the specific verbs andthe forms recorded is given in Appendix C.

The limited set of verbs recorded and stored for this project could beused with a course on MSA as demonstration examples for particular spoken

ARABIC 745

forms of verbs but it is not easily extended to include either additionalverbs or to present new forms of the verbs recorded. As a more generaland extendable system, we developed a second presentation mode that usesthe concatenation of affixes to syllables comprising stem verb forms. Thissecond mode allows us to present a fairly large selection of Arabic verbforms with very high quality using a medium size vocabulary of stem syl­lables and affixes. This mode plays an important role in increasing theflexibility of the presentations and is vital for transportation of the capa­bilities to other installations.

We have done basic research into the phonetic and intonational rela­tionships between the different parts of conjugated Arabic verbs. Thisresearch was then implemented experimentally on selected verb forms todetermine which aspects of the information were necessary for successfulsynthesis. Based on the experimental implementation, an algorithm wasdesigned to automatically provide the parameters necessary for synthesisof arbitrary Arabic verb forms from a syllabic inventory constructedfrom recorded, analyzed, and digitized verbs. This algorithm was inte­grated into the drill-and-practice instruction programs (see sec. 2 above).Of particular interest is the good quality achieved on verbs having pharyn­geal consonants, expected to be among the most difficult to synthesize.

Further steps taken with the synthesis of verb forms include the defini­tion and creation of a syllabic vocabulary, and the concatenation of demi­syllables (Lovins & Fujimura, 1976; Levine, 1981) to construct additionalsyllables forming different verbal stems of Arabic.

3.1 Phonemic Versus Syllabic Synthesis

A possible method for automatic generation of Arabic verbal forms istbe method of phoneme concatenation. In this method, individual pho­nemes (basic sounds) of Arabic would be stored and combined to generatethe different forms. This method is very attractive at first glance, since itprovides the fullest generality for formation of Arabic verbs. It is wellknown (Allen, 1977; Klatt, 1976), however, that there are many difficultieswith phoneme synthesis of English. The basic problem is that the phonemesof a word take on different phonetic colors depending on what otherphonemes are nearby. In Arabic, this problem is intensified, since thepresence of particular phonemes in a word can color other phonemes,even if the two are not adjacent (AI-ani, 1970, p. 30). The quality andnaturalness of the synthesized Arabic would not be acceptable for languageteaching, especially for distinguishing different verb forms, if we used asimple phoneme synthesis method of word formation.

Many phoneme-related problems are solved by concatenating largerlinguistic units, in particular: affixes, syllables, and demisyllables. Usingthese larger units results in more natural-sounding words since much of

746 A. LEVINE, MARKOS IAN, SEROPIAN & FERGUSON

the naturalness (and smoothness) of words is already present in these basicstored-sound units while it would have to be introduced when using thephonemic method, In particular, much of the problem of phonemes beingcolored by neighboring phonemes is solved by using syllables, since thesyllables already have the appropriate phonemes phonetically colored inrelation to each other.

3.2 An Example afAffixing

Consider the paradigm for the verb kataba ("to write") in MSA as dis­cussed above (see sec. I), Both the Active Imperfect and the Imperativeforms use the same stem ktub, together with the prefix ya- for the Imper­fect and ju- for the imperative, Each of the different verb stems, katab,ktub, kutib, and ktab, takes suffixes to indicate number, person, gender, andtense. Moreover, the stress on the stem syllables is different depending onthe suffix,

From recordings of these particular stems (as well as the affixes needed)we can synthesize the complete verbal paradigm for the verb kataba. Sincewe have accumulated a syllabic inventory for the verb stems, we neededthe syllables ha- k- ku- -tab, -tub, and -tib. We did not need separate copiesof the syllables for each verb form (e,g" there is only one syllable k- or -tabin the inventory). Additionally, other verbs which share syllables withkataba use the same inventory. We also have an inventory of the affixes(which are used for all verbs), including the prefixes ya- and ju-, and thesuffixes -a, -ta, -tunna, etc. (see Fig. 3.)

The verb paradigm for MSA includes information about the change instress pattern in the stem due to different suffixes. Thus, when the syllablesand affixes are concatenated to make the specific form of the verb, kataba,the intonational correlates of stress, pitch contour, duration of syllablesand relative loudness are determined by rule and applied, in real time usingMISS, to the concatenation to produce a natural-sounding verb form.

3,3 Syllabic Ajfixing

The verb conjugation pattern in Arabic consists of a consonantal rootwith a specific vowel pattern to which a small number of prefixes andsuffixes is added to indicate all conjugational categories as discussed above(see sec. 1). Rather than record all of the forms in the paradigm (for allnumbers, persons, genders, and tenses), we need only record and store thebasic different forms of the stems and provide automatic procedures foraffixing. Appropriate intonation modifications to both the stem and theaffixes are done as part of affixing. In order to provide additional flexibilityin handling stress placement in Arabic verb conjugations we use a systemwhich concatenates stem syllables together with the affixes and adjusts thestress of the different syllables as appropriate.

ARABIC 747

One part of the syllabic affixing system is the construction of an appro­priate set of syllables. For an initial set of sixty-six MSA verb stems, wecreated a vocabulary of fifty-three initial syllables and twenty-one finalsyllables. The lists of verb stems, and initial and final syllables are givenin Appendix E. From the list of verb stems it can be seen that there is alarge amount of overlapping' use of syllables in Arabic. We can estimate thata maximum of approximately 4,000 syllables will represent all the possiblestem syllables in MSA. It is, however, expected that co-occurrence restric­tions will reduce this number considerably further.

The syllabic vocabulary was constructed by excising the desired syllablesfrom occurrences of those syllables in recorded and LP analyzed MSA verbforms. In doing these excisions we relied on the overall consistency of thespeaker to insure that syllable durations and other phonetic featuresremained uniform in our vocabulary. One indication of this uniformity wasthe fact that both our initial and final stem syllables (largely CVC syllableswith some CV) had approximately equal durations: the average durationof a initial syllable was 239 ms (SD = ±98 ms) and the average duration ofa final syllable was 253 ms (SD ~ ±104 ms).

In addition to constructing a syllable vocabulary, we also constructed avocabulary of prefixes and suffixes. As displayed above in Figure 3, thereare eighteen suffixes (plus the null suffix). We excised the eighteen suffixeslargely from verbs in the /akala paradigm with six suffixes coming fromother verbs. The suffixes have a wide variety of durations (average dura­tion: 339 ms, SD = ±136 ms) since some of them are open monosyllableswhile others are bisyllabic, and some use long (doubled) vowels while othersuse short vowels.

The prefix vocabulary contains combinations of the nine MSA prefixes,as given in Figure 3, with the initial consonants from verbs that have acollapsed initial stem syllable. Each of the nine prefixes can potentiallycombine with any MSA consonant, requiring approximately 250 prefixsyllables to accommodate all the collapsed initial stem syllables, but manyof these prefixes overlap with the syllabic vocabulary that we constructed.The prefixes we have excised are quite short, in general, with averageduration of 151 ms (SD = ±1l9 ms), because most of the prefixes that werenot in our syllable vocabulary were open (CV).

For three-consonant-root primary verbs, the main word stress can beeither on the first or second syllable or on the suffix, depending on thesuffix attached. If the suffix begins with a "t" or "n", then the second stemsyllable gets the main stress except when the suffix is tunna, which itselfgets the main stress. For other suffixes (including the null suffix) the initialstem syllable in the verb gets the main stress. In many cases this is the firstsyllable of the verb when the first vowel in the root is elided and the prefixcombines with the first stem consonant as one syllable. In other words, as

748 A. LEVINE, MARKOSIAN, SEROPIAN & FERGUSON

is well established about Arabic, the stress is predictable and moves aroundin accordance with general rules (see AI-ani, 1970).

The placement of stress in the verb is accomplished by modifying thepitch contour, duration, and loudness of the syllables as they are concate­nated. The examples we recorded were of a female voice, so our pitch con­tours are stated with high pitch values. For a male voice the values shouldbe approximately two-thirds of those given. The durations of syllables asdiscussed here refer to their duration relative to their stressed duration.Thus we are shortening syllables when not in stressed positions, rather thanlengthening them for stress. Similarly, we discuss loudness as relative tothe peak loudness of the syllable when stressed. We have not been con­cerned with either the duration or loudness of the final stem syllable or theaffixes, since those aspects remain constant over the range of verbs we haveconsidered and thus are not changed, by our algorithm, from their re­corded values. It must be noted that we are concerned here with producingan algorithm for forming MSA verbs with proper stress patterns. It is quitelikely that different intonation contours can also induce the proper per­ception of stress.

The stressed syllable has a highest pitch of approximately 280 herz (hz).It also (obviously) has a full duration and full loudness since our basicunit is the stressed syllable. Depending on which syllable is being stressedwithin the word, the fall from the peak pitch value to the beginning of thenext syllable will be either 50 hz (initial stem syllable stressed), 80 hz (finalstem syllable stressed) or 100 hz (suffix stressed).

If the main stress falls on the initial stem syllable, the rest of the pitchcontour for the verb consists of a gentle rise to the peak value from 230 hzfollowed by a fairly steep fall to 150 hz. If the main stress falls on eitherthe final stem syllable or the suffix, the pitch contour for the verb consistsof a steep rise to the peak value from 180 hz (on the initial stem syllable)followed by a very steep fall to 150 hz. If there is a prefix syllable, thenthere is a fall from the prefix syllable to the initial stem syllable (from 230hz to 180 hz), followed, as above, by a rise to the peak value (280 hz). Thesecontours represent the citation form intonation patterns and would pre­sumably be different in sentential contexts.

Wheri the initial stem syllable is stressed, it takes its recorded durationand loudness (as do the rest of the concatenated syllables/affixes). If it is notstressed, it takes only three-fourths its recorded duration and half its loud­ness (approximately two just-noticeable-differences in amplitude).

3.4 Syllabic Versus Demisyllable Concatenation

Another alternative to syllabic (and -phonemic) concatenation for verbform synthesis is to use a dictionary of demisyllables to construct all thedesired forms. Demisyllables are sounds that are not complete syllables but

ARABIC 749

which combine several segmental sounds. For example, the English wordbed can be decomposed into two demisyllables which can be recombined toform polysyllabic words. To form bedding using the initial demisyllable be-,we also need two other demisyllables, -eddi- and -ing. These three demi­syllables, when concatenated, produce the full, polysyllabic word. Alter­natively, we can combine demisyllables to form syllables and then use syl­labic concatenation to form the polysyllabic words.

To generate all of the stems given above for the verb kataba, we wouldneed to have the following demisyllables: ka-, ku-, kta-, ktu-, -ata-, -aati-,-uti-, -ab, -ib, -ub, -uub. Since some of these demisyllables are also useful forother verb forms, a large savings in storage (when considering the entireverbal dictionary for Arabic) as well as great flexibility in verb productionis gained with this method. The problem of using demisyllables in this wayto form entire verb stems is that with different stress patterns on the dif­ferent syllables, we would need to shorten the first part of a -VCV- demi­syllable (e.g., -ata in this example) depending on the suffix (see above, sec.3.3). If we restrict the use of demisyllables to forming syllables, then thisproblem does not come up.

We estimate that fewer than 3,000 demisyllables are sufficient for gen­erating the verbal forms of Arabic. This number is somewhat smaller thanthe number of syllables (4,000) as estimated above. Both numbers areestimates based on the number of phonemes in Arabic and the restrictionson co-occurrence of phonemes. Furthermore, for generating dialectalvariations of the MSA verb forms, a small addition to the demisyllabledictionary would be sufficient to allow the basic algorithm to be expanded.

We have used the method of demisyllable formation of stem and prefixsyllables with good results. For example, given initial syllables na/ andtab we used demisyllables na- and -ab to form initial syllable nab (which wedid not have excised from our original recorded set of verbs). For twenty­one syllables formed in this manner, the duration was 255 ms (SD = ±94ms) which agrees well with the durations given above for excised syllables.

Thus the demisyllable method not only requires fewer recordings butwill give better results than the syllable method.

4. CONCLUSION

The VERPS project has shown that a language-instruction program canbe constructed for a complicated but regular part of a foreign language.While VERPS contains modules that are specific to Arabic, there are manyparts of the project that are general purpose. Thus this project couldfairly easily be adapted to work in some other domain, either some othergrammatical aspect of Arabic, another dialect or even a completely differentlanguage.

750 A. LEVINE, MARKOSIAN, SEROPIAN & FERGUSON

The drill program uses general purpose techniques applied to specificdata files for MSA in order to do verb-form recognition and generation.With comparatively little difficulty, the same techniqnes could be appliedto other data files to apply to different language-instruction problems.

This project covered many of the most common verbs (and verb conju­gations) in Arabic and thus demonstrated the feasibility of using synthe­sized speech for teaching Arabic. Automatic rules for forming verb con­jugations, using syllables, demisyllables, and affixes with appropriateintonation, provide a general method of generating additional verbs andverb forms as necessary. This approach is potentially capable of generatingall verbs (and verb conjugations) for Modern Standard Arabic as well asdifferent dialects of Arabic.

Two of the major factors which made the audio synthesis of MSA verbswork well were

1. the fact that the stress pattern for the different conjugations was very regularand essentially dependant on the suffix, and

2. the fact that in MSA syllabic structure is clearly delineated.

To apply the same techniques to other languages would require specifica­tion of the word stress rules (or some sort of stress marking) and would bedependent on the syllabic structure of the language. For example, it isreasonable to expect the technique to apply well to Hebrew, which is similarin these two respects to MSA, but not to English, which has more com­plicated word stress rules and has a less well delineated syllabic structurewith possible "intersyllabic" status for consonants.

An additional issue which needs to be investigated with regard to gen­eralizing the audio drills implemented here is the question of naturalness.We have tried to make the audio drills here sound natural as well as in­telligible, but the task is simpler for verb forms (which are only singlewords) than for longer utterances. Additional rules (possibly similar tothose used for English intonation; see Levine, 1979) would doubtless berequired for this problem.

REFERENCES

Abboud, P. F., Bezirgan, N. A., Erwin, W. M., Khouri, M, A., McCarus, F. A., &Rammuny, R. M. Elementary Modern Standard Arabic. Ann Arbor: University ofMichigan, 1975.

AI-ani, S. H. Arabic phonology: An acoustical and physiological investigation UanuaLinguarum, Series Practica, No. 61). The Hague: Mouton, 1970.

Allen, J. A modular audio response system for computer output. 1977 IEEE ICASSPRecord 1977, 77Ch1197-3, 597.

ARABIC 751

Brill, M. Basic Word List althe Arabic Daily Newspaper. Jerusalem: 1940.Cowan, D. Modern Literary Arabic. London: Cambridge University Press, 1958.Klatt, D. H. Structure of a phonological rule component for a synthesis-by-rule

program. IEEE Transactions on ASS?, 1976, 23, 391.Levine, A. Melodies and tones for analyzing intonation. Theoretical Linguistics,

1979,6(2/3), 117-143.Levine, A. The uses of LPC coefficient interpolation to improve the naturalness of

sentence formation by word concatenation. In P. Suppes (Ed.), University-levelcomputer-assisted instruction at Stanford: 1968-1980. Stanford, Calif.: StanfordUniversity, Institute for Mathematical Studies in the Social Sciences, 1981.

Lovins, J. B., & Fujimura, O. Synthesis of English monosyllables by demisyllableconcatenation. Journal oj the Acoustical Society of America, 1976, 60.S1.

Sanders, W. R., & Levine, A. The MISS speech-synthesis system. In P. Suppes(Ed.), University-level computer-assisted instruction at Stanford: 1968-1980. Stanford,Calif.: Stanford University, Institute for Mathematical Studies in the SocialSciences, 1981.

Scheindlin, R. 201 Arabic verbs fully conjugated in all the forms. Woodbury, New York:Barron's Educational Series, 1978.

APPENDIX A

ARABIC KEYBOARD

Arabic Character ; .to \:l,) t..Phonemic Transcription ?J T -G- 9English key I 2 3 4 5 6 7 8 9 0

Arabic Character U , u" ) ..... ~~ C Jio

~

Phonemic Transcription q w S r y u H ZEnglish key q w e r y u 0 p

Arabic Character,

U" <> .... e ... [: d J

Phonemic Transcription a s d f g h j kEnglish key a s d f g h J k +/;

) t u6.,

I;)Arabic Character U" "-! r ~

Phonemic Transcription z x D s b n m ?English key z x c v b n m ?/

752 A. LEVINE, MARKOSIAN, SEROPIAN & FERGUSON

Key to Verb Codes:

ac active ps passive :::c-

pf perfect ipf imperfect imp imperativeind indicative sbj subjunctive JS jussive1 first person 2 second person 3 third personsg singular dl dual pI pluralm male f female

Note: in the verb form list (Appendix B), square brackets, [ ... ], enclose alternative verbtenses to the form given. Thus, for example, the verb "ta/kuluu" can be either ac-ipf-sbj-2-m-plor ac-ipf-js-2-m-pl. If tenses are separated by a slash, (, inside of brackets then they are bothalternatives to the given form. For example, the verb "ta/kulna" can be either ac-ipf-ind-2-f-pl,ac-ipf-sbj-2-r..pl, or ac-ipf-js-2-f-pl. When there are two sets of brackets in a single form, thebrackets are independent. For example, the verb "ta/kulaa" can be ac-ipf-sbj-2-dl, ac-ipf-js-2-dl,ac-ipf-sbj-3-f-dl, or ac-ipf-js-3-f-dl.

APPENDIX B

A LIST OF VERBS

Form I ,jama9a gather fagala dobada/a begin baoa7a searchoacara attend 9alima learn, know9arafa know fataoa openqatala kill kataba writenapara see, watch darasa studytaraka leave ka7ura multiplysamaoa allow, permit 3ahaba goraja9a return sami9a hearvariba drink /akala eat/axa3a take waeala arrive

Form II

qarrara decide 9ayyana designate, appoint9allama teach /akkada assuredabbara manage earraoa explain

Form III

vaaraka share saafara travelfaaja/a confront, surprise jaawara adjoinfaa/ama blame waafaqa agree

Form IV

/axbara notify, inform /arsala send/a91ana proclaim, announce /a5laqa set free, launch/aqbala accept, receive

ARABIC 753

Form V

ta9allama learn ta/a77ara emulate, be influencedtabayyana perceive ta5awwa9a volunteertahayya/a get ready

Form VI

tabaadala exchange tanaawala acquire, taketasaajala inquire ta/aamara confer, plottaqaabala meet

Form VII

/in5afa/a be extinguished /inqa5a9a be brokenlin9aqada be held /infataoa be openedlinqalaba be overturned, become

Form VIII

lijtama9a assemble /intaxaba choose, electlintapara await /istama9a overhearlivtagala work /i9'aqada believe

Form IX"

libyacca become white /i9wajja bend/iefarra turn yellow, to pale

Form X

/ista9mala use listagbala meetlista/nafa resume listajwaba interrogate/istawrada import lista5aa9a be able to/istamadda take, partake /istafaada acquire, benefit

Doubled Verbs

panna think tamma be finishedpalla become /a9adda prepare/incamma unite /iotalla occupy/ic5arra be compelIed

Hollow Verbs

kaana be (past) qaala saydaama last jaa/a comeeaara become xaafa fear/araada want /imtaaza be distinguished

Assimilated Verbs

waca9a place wari7a inherit/awjaba require

Defective Verbs

da9aa call

754 A. LEVINE, MARKOSIAN, SEROPIAN & FERGUSON

APPENDIX C

LIST OF MSA VERB FORMS RECORDED

VERB: lakala (full paradigm recorded)

jakaltu ac-pf-I-sg jakalnaa ac-pf-I-pllakalta ac-pf-2-m-sg /akaltum ac-pf-2-m-pljakalti ac-pfC2-fCsg /akaltunna ac-pfC2-f-pl/akaltumaa ac-pf-2-dllakala ac-pf-3-m-sg lakaluu ac-pf-3-m-pllakalat ac-pf-3-f-sg /akalna ac-pf-3-fCpljakalaa ac-pf-3-m-dl /akalataa ac-pf-3-f-dl

(aakulu ac-ipf-ind-l-sg na/kulu ac-ipf-ind- I-pita/kulu ac-ipf-ind-2-m [3-f] -sg ta/kuluuna ac-ipf-ind-2-m-plta/kuliina ac-ipf-ind-2-f-sg ta/kulna ac-ipf-ind[sbj/js] -2-f-plya/kulu ac~ipf-ind-3-m-sg ya/kuluuna ac-ipf~ind-3-m-pl

tajkulaani ac-ipf-ind-2 [3-f] -dl ya/kulna ac-ipf-ind[sbj/js]-3-fCplya/kulaani ac-ipf-ind-3-m-dl

jaakula ac-ipf-sbj-l-sg na/kula ac-ipf-sbj-l-plta/kula ac-ipf-sbj-2-m[3-f] -sg ta/kuluu ac-ipf-sbj lis]-2-m-pltajkuJii ac-ipf-sbj lis] -2-f-sgya/kula ac-ipf-sbj-3-m-sg ya/kuluu ac-ipfCsbj lis]-3-m-plta/kulaa ac-ipf-sbj lis] -2 [3-f] -dlya/kulaa ac-ipf-sbj lis] -3-m-dl

laakul ac-ipf-js-l-sg na/kul ac-ipf-js-l-plta/kul ac-ipf-js-2-m [3-f] -sgya/kul ac-ipf-js-2-f-sg

kul ac-imp-2-m-sg kulii ac-imp-2-f-sgkulaa ac-imp-2-dlku!uu ac-imp~3-m-pl kulna ac-imp-3-f-pl

lukiltu ps-pf-I-sg jukilnaa ps-pf-l-pl/ukilta ps-pf-2-m-sg lukiltum ps-pf-2-m-pl/ukilti ps-pf-2-f-sg lukiltunna ps-pfC2-f-pllukiltumaa ps-pf-2-dl/ukila ps-pf-3-m-sg /ukiluu ps-pf-3-m-pl/ukilat ps-pf-3-f-sg /ukilna ps-pf-3-f-pljukilaa ps-pf-3-m-dl jukilataa ps-pf-"3-f-dl

/uukalu ps-ipf-ind-l-sg nu/kalu ps-ipf-ind-l-pltu/kalu ps-ipf-ind-2-m[3-f] -sg tu(kaluuna ps-ipf-ind-2-m-pltu/kaliina ps-ipf-ind-2-f-sg tu/kalna ps-ipf-ind [sbj/js ]-2-f-plyu/kalu ps-ipfCind-3-m-sg yu/kaluuna ps-ipf-ind-3-m-pl

ARABIC 755

tu/kalaani ps-ipICind-2 [3-f] -dlyu/kalaani ps-ipf-ind-3-m-dl yu/kalna ps-ipf-ind [sbj/js] -3-f-pl

/uukala ps-ipf-sbj-l-sg nu/kala ps-ipf-sbj-I-pltn/kala ps-iplCsbj-2-m[3-f] -sg tu/kaluu ps-iplCsbj [js]-2-m-pltu/kalii ps-ipf-sbj [js]-2-f-sgyu/kala ps-ipf-sbj-3-m-sg yu/kaluu ps-ipf-sbj [js]-3-m-pltu/kalaa ps-iplCsbj [js] -2 [3-f] -dl yu/kalaa ps-ipf-sbj [js] -3-m-dl

/uukal ps-ipf-js-I-sg nu/kal ps-ipf-js-l-pltn/kal ps-ipf-js-2-m[3-f] -sg yu/kal ps-ipf-js-3-f-sg

VERB: lakkada

-?

lakkadalakkadtijakkadtunna

VERB: bada/a

bada/abudijatnubda/utabdajiina

ac-pf-3-m-sgac-pf-2-f-sgac-pf-2-f-pl

ac-pf-3-m-sgps-pf-3-f-sgps-ipf-ind-l-plac-ipf-ind-2-f-sg

/ukkidaa/u/akkidunujakkidu

ps-pf-3-m-sgac-ipf-l-sgac-ipICI-pl

VERB: tabaadala

tabaadala ac-pf-3-m-sgtabaadalnaa ac-pf-l-pltabaadalaa ac-pf-3-m-dlyatabaadaluuna ac-ipf-ind-3-m-pl

VERB: jama9a

jama9tujama9atajma9iilijma9uujumi9at

VERB: oacara

oacarataocuraaninaocurujuocuruu

ac-pf-l-sgac-pf~3-m-sg

ac-ipf-sbj [js] -2-f-sgimp-2-m-plps-pf-3-fsg

ac-pf-3-m-sgac-ipf-ind-2 [3-f] -dlac-ipf-ind-l-plimp-2-m-pl

756 A. LEVINE, MARKOS IAN, SEROPIAN & FERGUSON

VERB: samaoa

samaotisamaoatasmaoiina/ismaoii

ac-pf-2-f-sgac-pf'3-m-sgac-ipf-ind-2-f-sgimp-2-f-sg

VERB: livtagala

/ivtagala/avtagilutavtagiluuna

VERB: earraoa

earraoaearraotumtuearriou

VERB: la51aqa

la51aqtula51aqala51iqlu5liqatyu5liquuna

ac-pf-3-m-sgac-ipf-ind-l-sgac-ipf-ind-2-m-pl

ac-pf-3-m-sgac-pf-2-m-plac-ipf-ind-2-m [3-f] -sg

ac-pf-I-sgac-pf-3-m-sgimp-2-m~sg

ps-pf-3-f-sgac-ipf-ind-3~m-pl

/ivtagalnaa

tuearriona

ac-pf-I-pl

ac-ipf-ind [sbj/js]-2-f-pl

VERB: li9taqada

li9taqadata9taqidiinana9taqidu

ac-pf-3-m-sgac-ipf-ind-2-f-sgac-ipf-ind-I-pl

In addition to the above paradigms which were recorded, the ac-pf-3~m-sg forall of the verbs in Appendix B were also recorded.

APPENDIX D

TRANSCRIPT OF USER INTERACTION WITH THE ARABIC PROGRAM

Following is an annotated transcript of a sample interaction with the input andoutput grammars. The user's typed input is indicated by underscoring. Commentsappear to the right following a semicolon.

ARABIC 757

@!!.&!:.SAV;lReading affixReading stem

filefile

, !

" !

; Start the program:; The grammars are initialized by; reading verb data files.

Reading irregular verbs file ...Reading input grammar fileReading form spec file .. !Do you want audio?(Type Y, N, (cr), or ?) * H

Input grammar(Type I or 0)Arabic output

or output* Qgrammar.

; no audio this time!; audio causes tokens to be spoken.

grammar??

Type a verb form speci~ication:

stem * ? ; Typing.£. will get the program to; describe the options available at; any point. Here, it prints the list; of all verb stems it knows about.

Type one of the following Arabic verb stems, with or without vowels:

jamaS fa9al bada/ baoa7 oacar 9alim 9araf fataoqatal katab napar daras tarak ka7ur samao 3ahabraja9 sami9 varib /akai /axa3 waeai qarrar 9ayyan9aiiam /akkad dabbar earrao vaarak saafar faaja/ jaawariaa/am waafaq xbar rsai 9ian 5laq qbai ta9ailamta/a77ar tabayyan ta5awwa9 tahayya/ tabaadai tanaawal tasaa/al ta/aamartaqaabal nqalab n5afa/ nqa5a9 n9aqad nfatao jtama9 ntaxabntapar stama9 vtagai 9taqad efarr byacc 9wajj sta9maistaqbal sta/naf stajwab stawrad stafaad sta5aa9 stamadd

Or, type R(cr)'z

to repeat (speak) current verb-formlast stem entered.to return to top level

stem ; The user selects a verb stem. He; could have typed f91, since the; consonants alone uniquely identify; the stem.

form spec * 1. ; Again, a 1. gets a list of options­; here, the various ways of; specifying a form.

Type ( cr)(form spec)

(n)

; last form spec entered; any form spec as listed in

(ARABIC)VERB.*; n-th form spec as listed in

(ARAB IC)VERB.*; preceding form spec (ordered by

index)

758 A. LEVINE, MARKOS IAN, SEROPIAN & FERGUSON

>·Z

form spec * ~

fa9al ti

Type a verb form specification:

'stem *

[fa9al]

form spec* ac-ipf-3-m-sg-ind

AOG( f91. ac-ipf-ind-3-m-sg [18] ):

ya f9al u

Type a verb form specification:

stem *[ fa9al]

form spec& ps-ipf-3-f-sg-sbi

AOG( f91, ps-ipf-sbj-3-f-sg [90] ):

tu f9al a

; next form spec (ordered by index)

; to return to top level

; Here, the user selects the 3rd; form specification as arranged in; the list of form specs.

; The program responds by' printing; stem, form specification, and the; actual verb form, as indicated; below (AGe denotes "Arabic; Output Grammar."). The verb; form is split into stem and suffix.; Note that this particular form [3]; takes no prefix.

; Next, the program requests; another form specification.

; User just types carriage return to; request same stem as before.; The program confirms previously­; selected stem.

; This time, the user actually

; specifies the complete form name; (instead of its number).

; This particular form has both; prefix and suffix. Note the; elision of the first vowel in the stem; (fa9al became f9al).

ARABIC

Type a verb form specification:

759

stem *[fa9a1]

form spec * imp-ac-2-m-sg

AOG( f91, ac-imp-2-m-sg [53] ):

/if9a1

Type a verb form specification:

stem *[fa9a1 ]

form spec * Q

AOG( f91, ac-pf-3-f-sg [5] ):fa9a1 at

Type a verb form specification:

stem *[ fa9a1]

form spec * >

AOG( f91, ac-pf-2-d1 [6] ) :fa9a1 tumaa

Type a verb form specification:

stem *[ fa9a1]

form spec * >

AOG( f91, ac-pf-3-m-d1 [7] ):

Type a verb form specification:

stem *[ fa9a1]

form spec *>

AOG( f91, ac-pf-3-f-d1 [8] ):

Type a verb form specification:

stem

ragal aa

ra9al ataa

; User exits from output grammar... and selects input grammar.

Input grammar or output grammar??

760 A. LEVINE, MARKOS IAN, SEROPIAN & FERGUSON

(Type I or 0) * I

Arabic input grammar.Token to parse * tafa9ala

PARSE ( tafa9ala ):(("ta'l llfa9aP' 11 a ll))

AGR: NIL

Token to parse * tuf9ala

; An invalid token, although the; prefix, stem and suffix are each; valid.

; The program succeeds in parsing; the token into affixes and stem;. . but reports the combination is; invalid.

; A valid Arabic verb token with; TWO corresponding form; specifications

ps~ipf-sbj-2-m-sg

ps-ipf-sbj-3-f-sg

PARSE (({ "tullAGR:8990

tuf9ala ):rrf9a!" "a"))

; The program provides a list of form; specifications that match the verb.

APPENDIX E

SYLLABIC INVENTORY FOR MSA VERB STEMS

Initial syllables used to form limited set of MSA verb stems

la la5 laa lab laj las lib lli /islu /u5 lub luj luo luu ba baa buear eur ja JU oa sanal nab naJ nao nas nul nu5 nub nujta tal tab taj tao tas tul tu5 tub tujyal yab yaJ yas yul yu5 yub YUJ null

Final syllables used to form limited set of MSA verbs

carkalma9

curkilmao

dalkulmig

dalkkadqad

dilkkidqid

gallaqrao

gilIiqrio

ARABIC 761

Limited set of MSA verb stems

lajma9 lujma9 nujma9 tujma9 yUjma9lijma9 najrna9 tajma9 yajma9

labdal lubdal nubdal tubdal yubdallibdal nabdal tabdal yabdal

la5laq lu51aq nu51aq tu5laq yu5laqla.5liq lu51iq nu51iq tu5liq yu5liqlakal /uukal nu/kal tu/kal yu/kallaakul lukil na/kul ta/kul ya/kul kul/asmao lismao nasmao tasmao yasmao samaolakkad lakkid lukkidearrao earno eurrin

/uocur naocur taocar oacarbaadal badal budil jama9 jumi9ragal tagil taqad taqid

_or-