1 Batxillerat1 BatxilleratInstitut de VilafantInstitut de Vilafant

What’s a modal verb?What’s a modal verb? Modals (also called Modals (also called modal verbs, modal modal verbs, modal

auxiliary verbauxiliary verbs, s, modal auxiliariesmodal auxiliaries) are ) are special verbs which behave irregularly in special verbs which behave irregularly in English. English.

They are different from normal verbs like "work, They are different from normal verbs like "work, play, visit..." play, visit..."

They give additional information about the They give additional information about the functionfunction of the main verb.  of the main verb.

They have a great variety of They have a great variety of communicative communicative functionsfunctions. .

CharacteristicsCharacteristics They never change their form. You can't add "s", "ed", They never change their form. You can't add "s", "ed",

"ing"..."ing"... We make the negative form using ‘not’.We make the negative form using ‘not’. We can use contractions in the negative form.We can use contractions in the negative form. There’s subject – modal inversion in questions.There’s subject – modal inversion in questions. They are always followed by an infinitive without "to“.They are always followed by an infinitive without "to“. They indicate modality and allow speakers to express They indicate modality and allow speakers to express

permission, ability, obligation, prohibition, lack of permission, ability, obligation, prohibition, lack of necessity, advice, possibility, probability.necessity, advice, possibility, probability.

Ability and requestsAbility and requests CAN CAN COULD (ability in the past / polite permission)COULD (ability in the past / polite permission) BE ABLE TOBE ABLE TO MANAGED TOMANAGED TO

I I can play handball / He can’t singcan play handball / He can’t singHe was able to walk when he was 2He was able to walk when he was 2It was difficult but I managed to find the solutionIt was difficult but I managed to find the solutionExcuse me, could you help me?Excuse me, could you help me?

Obligation and Obligation and ProhibitionProhibition

HAVE TOHAVE TO – I have to buy a new shirt. – I have to buy a new shirt. MUST MUST – You must stop when the traffic lights – You must stop when the traffic lights

are red.are red. MUSTN’TMUSTN’T- You mustn’t smoke in a hospital.- You mustn’t smoke in a hospital.

Absence of obligationAbsence of obligation DON’T / DOESN’T HAVE TODON’T / DOESN’T HAVE TO He doesn’t have to buy tomatoes. There He doesn’t have to buy tomatoes. There

are a lot in the fridge.are a lot in the fridge.

NEEDN’T - DON’T / DOESN’T NEED TONEEDN’T - DON’T / DOESN’T NEED TOYou needn’t / don’t need to buy any You needn’t / don’t need to buy any

books. books. You can use the ones in the library.You can use the ones in the library.

SHOULDSHOULD SHOULDN’TSHOULDN’T OUGHT TO OUGHT TO OUGHTN’T TOOUGHTN’T TOThey should revise before the test.They should revise before the test.You ought to apologise. Your comment You ought to apologise. Your comment

was too rude.was too rude.

PossibilityPossibility

MAY / MAY NOT MAY / MAY NOT ( more possible)( more possible) MIGHT / MIGHT NOT MIGHT / MIGHT NOT (less possible)(less possible) COULDCOULD

I’ll call Jane. She might not remember our date.I’ll call Jane. She might not remember our date.This could be right.This could be right.

Logical deduction/ Logical deduction/ CertaintyCertainty

MUSTMUST CAN’TCAN’T

She must be tired. She’s been running for 50 Km.She must be tired. She’s been running for 50 Km.He can’t be poor. Have you seen his car?He can’t be poor. Have you seen his car?

(There is some evidence)(There is some evidence)

Modal perfects IModal perfects I MODAL VERB + HAVE + P. PPLEMODAL VERB + HAVE + P. PPLE Used to talk about past events Used to talk about past events

must have + past pplemust have + past pple. → . → logical deduction about the pastlogical deduction about the pastThe teacher must have been disappointed after The teacher must have been disappointed after correcting the tests.correcting the tests.

can’t have + past pplecan’t have + past pple. → . → impossibility in the pastimpossibility in the pastYou can’t have seen Ben. He is in New Zealand.You can’t have seen Ben. He is in New Zealand.

may / might/could+ have+ past pplemay / might/could+ have+ past pple. →. →possibility in the pastpossibility in the pastSarah is not here. She might have gone to the cinema.Sarah is not here. She might have gone to the cinema.

could have + past pple. → to suggest an alternative past action could have + past pple. → to suggest an alternative past action even though it is now too late even though it is now too late

You could have bought something different.You could have bought something different.

Modal perfects IIModal perfects II should have + past pple. → we wish something should have + past pple. → we wish something

had happened in the past, but it didn’t happenhad happened in the past, but it didn’t happenWe should have stayed out. It was a fantastic We should have stayed out. It was a fantastic

night.night.

shouldn’t have + past pple. → we wish shouldn’t have + past pple. → we wish something had not happened in the past, but it something had not happened in the past, but it did happen.did happen.

They shouldn’t have watched a horror film. They shouldn’t have watched a horror film. They They can’t sleep now.can’t sleep now.