An Introduction to Language 2012 FALL - ajou.ac.kr

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SEMANTICS: THE MEANING OF LANGUAGE An Introduction to Language 2012 FALL

Transcript of An Introduction to Language 2012 FALL - ajou.ac.kr

SEMANTICS:

THE MEANING OF LANGUAGE

An Introduction to Language

2012 FALL

Semanticshttp://www.etymonline.com

Science of meaning in language

Greek semantikos sema "sign”

ics : a suffix of nouns that denote a body of facts, knowledge, principles

e.g.) ethics, physics, politics

image/concept

The Semiotic triangle (Ogden & Richards, 1923)

object/referent word/symbol

What is Semantics?

The study of the linguistic meaning of

morphemes, words, phrases, and sentences

Subfields

Lexical Semantics: the meanings of words

Phrasal/Sentential Semantics: the meaning of

syntactic units larger than the word

Pragmatics: The study of how context affect

meaning e.g.) It’s cold in here.

Sentential meaning

entailment

tautology vs. contradiction

Compositional Semantics

Anomaly vs. metaphor vs. idioms

Lexical Semantics

Sense vs. reference

Lexical relations

Semantic features

Argument structure: Thematic roles

Speakers’ knowledge of meaning includes

The truth conditions of sentences

when one sentence entails another

When two sentences are paraphrases

or contradictory

When a sentence is a tautology,

contradiction or paradox

When sentences are ambiguous

Truth-conditional/compositional Semantics

Truth conditions: Most sentences are true or

false in a given situation

STNs that are always true

Tautologies/analytic

STNs that are always false

=> Contradictions

Truth-conditional/compositional Semantics

Circles are round. A bachelor is single.

=> Tautologies

Circles are square. A bachelor is married.

=> Contradictions

Cf) All students are liars. (A student says this)

=> paradoxes

Entailment and Related Notions

1) Entailment holds the meaning relation

between sentences (propositions);

A entails B if whenever A is true B is also

true, in all conceivable circumstances

e.g. Jack swims beautifully (A) entails

Jack swims (B).

Entailment vs. synonymy

2) Two sentences ______________

(paraphrases) if they entail each other.

e.g. Jack put off the meeting.

= Jack postponed the meeting.

synonymous

Entailment vs. contradiction

3) Two sentences are ______________

if one entails the negation of the other.

Two sentences are contradictory if,

whenever A is true, B is false.

e.g. ‘Jack is alive’

‘Jack is dead’ (=Jack is not alive)

contradictory

Ambiguity with PS trees

e.g. The boy saw the man with the telescope.

S S

NP VP NP VP

VP PP V NP

The boy saw the man with the telescope The boy saw NP PP

the man with the telescope

SEMANTIC AMBIGUITY

Semantic ambiguity results from different

PS structures.

=> Principle of Compositionality: the

meaning of a sentence is composed of the

meanings of its parts(words/expressions)

and how they are combined structurally.

Compositional Semantics

What is the meaning of the sentence Jack swims?

a) Word Meanings:

Jack - refers to the individual Jack.

Swims - refers to the set of individuals that swim

b) Syntactic Structure S

NP VP

Jack swims

Entailment & Rules

‘Jack swims beautifully’

Any truth condition that causes Jack

swims beautifully (A)to be true

necessarily causes Jack swims (B) to

be true, hence A entails B.

Counterexamples to Compositionality

1) Anomaly

a) semantic violations

Colorless green ideas sleep furiously.

[without color] + [green in color]

b) Semantic violations in poetry=> metaphor

a week ago [temporal semantic feature] vs.

a grief ago [an unhappy time after a sad event]

Counterexamples to Compositionality

2) Metaphor (<= anomaly)

a) literal & metaphorical meanings => ambiguity

b) Accommodate meaning w/ semantic properties

e.g. Walls have ears.

c) the word meaning + facts about the world.

e.g. Time is money.

d) cultural components: a bug in my program.

e) Relate to language creativity and change

e.g. the fall of the dollar

Counterexamples to Compositionality

3) Idioms/Idiomatic phrases (<= metaphor)

a) Idioms have fixed meanings (not compositional)

b) Idioms are frozen in form

e.g. She put her foot in her mouth.

?Her foot was put in her mouth.

c) Idioms violate semantic restriction

e.g. He ate his hat.

d) Idioms are stored as single items in the lexicon

LEXICAL SEMANTICS

Theories of Word Meaning

1) referent: The meaning of a word is its reference,

its association with the object it refers to.

a) The NP refers to the individual Jack.

e.g. Jack swims.

b) Not every NP refers to an individual.

e.g. No baby swims.

c) Two different NPs with the same referent.

e.g. Barack H. Obama vs. the president of the U.S.

Theories of Word Meaning

2) Sense: the way we think about an expression

a) The president: ‘the head of the state’

cf) ROH, Moo-hyun / LEE, Myungbak

b) Proper names have sense but no reference

e.g.) Harry Potter

3. 2 Lexical Relations

1) Synonyms: different words w/ similar meaning

a) No perfect synonyms e.g. sofa vs. couch

b) Many French loanwords: manly vs. virile

2) Antonyms: words that are opposite in meaning

a) Complementary pair: alive/dead (not A = B)

b) Gradable pair: big/small (not A ≠ B)

c) Relational opposites: teacher vs. student

cf) autoantonyms: cleave

3) different words/same pronunciation

a) ambiguity: I’ll meet you by the bank

b) humor/confusion: flour vs. flower

bare and bear are __________ (also called

___________) which are words that have

different meanings but are pronounced the

same, and may or may not be spelled the

same. They are _____________ when spelled

the same as in bow but called ___________

when pronounced differently as in pussy.

homonyms

homophones

homographs

heteronyms

4) Polysemy: multiple meanings with a conceptual

or historical link

bear1: i) tolerate ii) carry iii) support

bear2: a large strong animal with thick fur

bare: i) without clothes ii) not covered/empty

=> bear1 and bare are ______________, while

bear1, bear2, bare are ___________.

polysemous

homonyms

5) Hyponyms: specific instances of a general word

e.g. red, white, blue /color

- X is a hyponym of Y; Y has the hyponym X

=> Y is a hypernym of X

Y (general category)

X (specific components)

3. 3. Semantic Features

a formal device indicating the presence or

absence of semantic properties

tigress, doe, ewe, hen, mare

aunt, debutante, girl, maiden, widow

father, uncle, bachelor

bring, fall, plod, walk, run, …

hit, kiss, touch, …

see, hear, feel

+ animate – animate vs. + human - human

+female

+human +female

+human –female

+motion

+contact

+sense

Semantic Features of Nouns

Decomposing into semantic features

woman father girl cock rice

+count + count +count + count -count

+human +human +human -human -human

+female -female +female -female . . .

-young -young +young . . . . . .

. . . . . . . . . . . . . . .

*He has two rices.He has a cock. vs.

Semantic Features of Verbs

i) Verbs can be broken down into semantic

features.

darken cause to become dark.

kill cause to die

uglify cause to become ugly

=> [cause]

Semantic Features of Verbs

ii) eventive vs. stative distinction

EVENTIVES

Mary was kissed by John.

John is kissing Mary.

Kiss Mary!

John deliberately kissed Mary.

Semantic Features of Verbs

ii) eventive vs. stative distinction

STATIVES

?Mary was known by John.

?John is knowing Mary.

?Know Mary!

?John deliberately know Mary.

Semantic Features of Verbs

iii) Negation: Negative polarity item – NPI

John thinks that he’ll ever fly a plane anymore.

John doesn’t think that he’ll ever fly a plane anymore.

John hopes that he’ll ever fly a plane anymore.

John doubts that he’ll ever fly a plane anymore.

John despairs that he’ll ever fly a plane anymore.

Semantic Features of Verbs

iii) Negation: Negative polarity item – NPI

*J thinks that he’ll ever fly a plane anymore.

J doesn’t think that he’ll ever fly a plane anymore.

*J hopes that he’ll ever fly a plane anymore.

J doubts [think that not] that he’ll ever fly a plane anymore.

J despairs [has no hope] that he’ll ever fly a plane anymore.

ARGUMENT STRUCTURE

a) C-selection

i) The various NPs occurring w/ a verb: arguments

Intransitive verbs have one argument: S

Transitive verbs have two arguments: S O

Di-transitive verbs have three arguments: S IO DO

ii) The argument structure of a verb is part of its

meaning AND included in its lexical entry.

ARGUMENT STRUCTURE

b) S-selection

the verb limits the semantic properties of

both its subject and its complements

Colorless green ideas sleep furiously

[sleep s-select animate subjects]

Our knowledge of verbs include

their syntactic category

which objects they select;

the thematic roles that their NP

subject and object(s) have.

THEMATIC ROLES

¶ agent: the doer of the action

¶ theme: the undergoer of the action

¶ goal: the endpoint of a change in location or

possession

¶ source: where the action originates

¶ instrument: the means used to accomplish

the action

¶ experiencer: one receiving sensory input

THEMATIC ROLES

The boy found a red brick.(agent) (theme)

The boy threw the red ball to the girl.(agent) (theme) (goal)

The boy bought the red ball from John.(agent) (theme) (source)

The boy opened the door with the key.(agent) (theme) (instrument)

THEMATIC ROLES

The boy saw the man with a telescope (experiencer) (theme) (instrument)

The boy hit the man with a ball.(agent) (theme) (instrument)

THE SAME THEMATIC ROLES

The dog bit the stick.(agent) (theme)

The stick was bitten by the dog(theme) (agent)

The trainer gave the dog a treat(agent) (goal) (theme)

The trainer gave a treat to the dog.(agent) (theme) (goal)

THEMATIC ROLES DON’T CHANGE

The boy opened the door with the key.(agent) (theme) (instrument)

The boy opened the door.(agent) (theme)

The door opened.(theme)