Modal VerbsModal VerbsShould / Shouldn’tShould / Shouldn’t

Must / Mustn’tMust / Mustn’tCan / Can’tCan / Can’t

May / Might / Might notMay / Might / Might notCould / Couldn’tCould / Couldn’t

Have to / Don’t have toHave to / Don’t have toBe able toBe able to

Modal verbsModal verbs: differences : differences with normal verbswith normal verbs

RULESRULES EXAMPLESEXAMPLESNo –sNo –s in the 3rd person in the 3rd person of the Present Simple of the Present Simple tense.tense.

He He mustmust go to the doctor. go to the doctor.

Negatives and Negatives and questions questions without do / without do / doesdoes..

I I can’tcan’t (can not) speak (can not) speak Chinese.Chinese.

CouldCould you swim when you you swim when you were four years old?were four years old?

They go with another They go with another verb in bare infinitive.verb in bare infinitive.

You You should should buybuy a new pair a new pair of shoes.of shoes.

Many modal verbs do Many modal verbs do not have past or future not have past or future forms.forms.

We We will canwill can go to the go to the cinema tomorrow.cinema tomorrow.

USE:USE: Should / Shouldn’t Should / Shouldn’t

To To give advicegive advice (donar consells):(donar consells):

To To make make suggestionssuggestions (fer (fer suggeriments):suggeriments):– You should buy this You should buy this

dress, it is very dress, it is very beautiful.beautiful.

USE: USE: mustmust

To express To express necessitynecessity, , strong strong recommendationrecommendation or or obligationobligation::– You must be quiet in the library.You must be quiet in the library.– You must protect your skin with You must protect your skin with

suncream.suncream.– Students must get a 5 to pass the Students must get a 5 to pass the

English test.English test.

1 2 3

USE: USE: mustmust

To express To express certainty that something certainty that something is true:is true:– You must be John’s son. You must be John’s son.

USE:USE: mustn’t mustn’t

To express that To express that something is something is forbiddenforbidden (prohibited) or (prohibited) or wrongwrong

USE: USE: can / can’tcan / can’t

To express To express ability ability (habilitat, saber (habilitat, saber fer), fer), possibilitypossibility, to ask for and give , to ask for and give permissionpermission, and to make , and to make requests requests andand offers offers (demanar i oferir):(demanar i oferir):– Can we play Wii this afternoon?Can we play Wii this afternoon?– We can go home by car.We can go home by car.– Susan can play the guitar.Susan can play the guitar.– Can I help you?Can I help you?– Can I go to the toilet, please?Can I go to the toilet, please?

USE:USE: can’t can’t

To express To express certainty that something certainty that something is not possibleis not possible::– He can’t be our new coach.He can’t be our new coach.

USE: USE: may (not)may (not)

To express To express possibility:possibility:– We may go to the beach this weekend.We may go to the beach this weekend.

To make a polite To make a polite request request oror offer: offer:– May I take a sweet?May I take a sweet?

USE: USE: might (not)might (not)

To express a remote To express a remote possibility:possibility:– We might go on holidays to New York We might go on holidays to New York

this year.this year.

USE: USE: could / couldn’tcould / couldn’t

To express ability and possibility, To express ability and possibility, in the in the pastpast::– CouldCould you play the piano when you were you play the piano when you were

four?four?– The weather was bad yesterday so we The weather was bad yesterday so we

couldn’tcouldn’t go to the beach. go to the beach. To make suggestions and polite To make suggestions and polite

requests:requests:– We We couldcould go to the zoo tomorrow. go to the zoo tomorrow.– CouldCould I borrow your pencil, please? I borrow your pencil, please?

Have to: FORMHave to: FORM

Have toHave to can be considered a can be considered a semi-modalsemi-modal verb because it is a little bit different:verb because it is a little bit different:– The 3rd person singular is made with The 3rd person singular is made with hashas::

She She has tohas to do her homework. do her homework.

– The negative form is made with The negative form is made with do / doesdo / does:: YouYou don’t have to don’t have to wear a tie to come to classwear a tie to come to class..

– It can be used in past and future tenses:It can be used in past and future tenses: I I had tohad to go to the hairdresser last week. go to the hairdresser last week.

USE:USE: have to have to

To express To express obligationobligation or or necessitynecessity::– Mike Mike has tohas to turn in a project tomorrow. turn in a project tomorrow.

USE:USE: don’t / doesn’t have todon’t / doesn’t have to

To express that something is To express that something is not not necessarynecessary::

What is the difference betweenWhat is the difference between have to have to andand must? must?

To express that the obligation / To express that the obligation / necessity comes from the speaker’s necessity comes from the speaker’s point of view we usepoint of view we use must: must:– I I mustmust stop smoking (I want to, it is my stop smoking (I want to, it is my

decision)decision) To express that the obligation / To express that the obligation /

necessity comes from outside we usenecessity comes from outside we use have to:have to: – I I have tohave to stop smoking (the doctor says it). stop smoking (the doctor says it).

Be able to: FORMBe able to: FORM

Be able toBe able to can be considered a can be considered a semi-semi-modalmodal verb, too: verb, too:– The verb The verb to beto be is used in all its forms is used in all its forms

and tenses:and tenses: John was able to catch the train on time.John was able to catch the train on time. Will you be able to buy some bread?Will you be able to buy some bread? She has never been able to swim for 60 She has never been able to swim for 60

minutes. minutes.

Summary: Use of modal Summary: Use of modal verbsverbs

Should Should

Shouldn’tShouldn’tAdviceAdvice You You shouldshould wear a coat. wear a coat.

SuggestionsSuggestions You You shouldshould buy this dress. buy this dress.

MustMust NecessityNecessity Students Students mustmust get a 5 to pass the get a 5 to pass the test.test.

Strong Strong recommendatirecommendationon

You You mustmust protect your skin with protect your skin with suncream.suncream.

ObligationObligation You You mustmust be quiet in the library. be quiet in the library.

Mustn’tMustn’t ProhibitionProhibition You You mustn’tmustn’t cross the street in a cross the street in a

red light.red light. Something Something wrongwrong

You You mustn’tmustn’t shout to your parents. shout to your parents.

CanCan

Can’tCan’tAbilityAbility I I can’tcan’t speak Chinese. speak Chinese.

PossibilityPossibility We We cancan go home by car. go home by car.

PermissionPermission You You cancan watch TV now. watch TV now.

Offer Offer CanCan I help you? I help you?

RequestRequest CanCan I borrow your pencil, please? I borrow your pencil, please?

Summary: Use of modal Summary: Use of modal verbsverbs

Could Could

Couldn’tCouldn’tAbility in the Ability in the pastpast

I I couldcould play the piano when I was play the piano when I was four.four.

Possibility in Possibility in the past.the past.

We We couldn’tcouldn’t go to the beach go to the beach because it was cloudy.because it was cloudy.

Polite requestsPolite requests CouldCould I have a cup of coffee, I have a cup of coffee, please?please?

SuggestionsSuggestions We We couldcould go to the zoo tomorrow. go to the zoo tomorrow.

Have toHave to Obligation / Obligation / NecessityNecessity

Mike Mike has tohas to turn in a project turn in a project tomorrow.tomorrow.

Don’t / Don’t / Doesn’t Doesn’t have tohave to

Something not Something not necessarynecessary

You You don’t havedon’t have to bring anything to bring anything to the party (but you can).to the party (but you can).