Modals and semi-modals

Modals and semi-modals

Modals Can, may, must… They are the same for all

persons. You must pay attention.

They don’t need an auxiliary verb for questions and negatives: You shouldn’t swim when it’s

windy. Should I stay with you?

Two modal verbs can’t be used in the same phrase: I will can play again next

month (*).

Semi-modals Be able to, have to They aren’t the same for all

persons. You have to pay attention / She has

to pay attention. They may need an auxiliary for

questions and negatives: You don’t have to say you’re sorry. Do we have to speak in English?

They’re used when the modals can’t be used. I will be able to play again next

month.

SIMPLE MODALSMust / have to Obligation I must go to the hospital

Logical deduction (only must) The film must be very good. Everybody likes it.

Can’t Logical deduction This person can’t be Michael. He’s too short.

Don’t have to Lack of obligation You don’t have to say you love me.

Mustn’t / can’t Prohibition We mustn’t smoke at school.We can’t skip classes.

Can (past, could) / be able to

Ability She can swim very fast. I couldn’t concentrate yesterday.Next year, I will be able to speak three languages.

Should / ought to Advice You should listen to your teachers.

May / might Possibility It may rain this afternoon. It’s very cloudy.

Can / could / may permission Can I come in, please?

Shall Offering (used only in questions and with 1st persons) Shall we continue?Shall I give you my phone number?

PERFECT MODALSPERFECT MODALS: MODAL + HAVE + PAST PARTICIPLE

Should have Criticism about a past action You should have made a bigger effort.You shouldn’t have used the present simple so often.

Must have Logical deduction about something in the past

It must have been love, but it’s over now.You must have worked very hard. I can see you’re so tired!

Could have Ability to have done something which wasn’t done.

You could have written some more.

Couldn’t have Disbelief You couldn’t have finished so quickly. It’s impossible!

Needn’t have An unnecessary past action You needn’t have brought that bottle of wine. We have got plenty of it here.

Might / may have Guessing about a possibility in the past

She might have forgotten to do her homework.

Would have Past conditional: you wanted to do something, but you couldn’t

I would have gone to her party, but I wasn’t invited.