English: modal auxiliary verbs (theory and examples)

They are used before the infinitives of other verbs.

They add certain kinds of meaning connected with certainty, or with obligation and freedom to act.

They are:

Can Could May Might Will Would Shall (maily in British English) Should Must Ought

They have no ‘s’ in the 3rd person singular

Questions, negatives, tags and short anwers are made without ‘do’.

Can you swim? Yes, I can.

He shouldn’t be doing that, should he?

She may know his address

With the exception of ‘ought’ , we use the infinitive without ‘to’ (bare infinitive)

Continuous, perfect and passive infinitives are also possible

They do not have infinitives or participles.

I may not be working tomorrow.She was so angry she could have killed him.The kitchen ought to be paintedone of these days.

I must water the flowers.You ought to water the flowers.

To mayMayingMayed

Do not exist

They do not normally have past forms, (although would, should, could and might are sometimes used as past tenses of will, can, shall and may.)

Certain past ideas can be expressed by a modal verb followed by a perfect infinitive.◦ Formed: have + past participle

You should have told me you were coming.I think I may have annoyed Aunt Mary.

Modal verbs have a contracted negative form which are used in an informal style.◦ Shan’t and Mayn’t are used in British English,

but Mayn’t is very rare.

Need and used to◦ These are sometimes used in similar ways to

modal verbs. You needn’t wait for me. She used not to be so bad tempered.

Not for situations that definitely exist.

Not for particular events that have definitely happened.

We use them to talk about things:

Which we expect Which are or are not possible Which we think are necessary Which we want to happen Which we are not sure about Which tend to happen Which have not happened

The meanings of modal verbs can be divided into two main groups.

Degrees of certainty

Obligation, freedom to act and similar ideas (very important in the polite expression of requests, suggestions, invitations and instructions)

Complete certainty (possitive or negative) shall, will, must, can’t

Probability (deduction; saying that something is logical or normal) should, ought to

I shall be away tomorrow.I shan’t be late on Tuesday.It won’t rain this evening.That can’t be John, he is in Dublin.There’s the doorbell, that’ll be Tony.Things will be alright.You must be tired.

She should/ought to be here soon.It shouldn’t / oughtn’t to be difficult to get there.

Possibility (talking about the chances that something is true or will happen.) May

Weak possibility: might, could

I might see you again, who knows?Things might not be as bad as they seemWe could all be millionaires one day.

The water may not be warm enough to swimWe may be buying a new house.

Strong obligation – must, will, need

Prohibition – must not, may not, cannot

Weak obligation; recommendation – should, ought to, might, shall (in questions)

Students must register in the first week of term.All sales staff will arrive for work by 8.40 a.m.Need I get a visa for Hungary?Students must not use the staff car park.Books may not be taken out of the library.You can’t come in here.

You should try to work harder.She really ought to wash her hair.You might see what John thinks.What shall we do?

Willingness, volunteering, resolving, insisting and offering – will, shall (in questions)

Permission – can, could, may, mightYou can use the car if you like.Could I talk to you for a minute?May we use the phone?Do you think I might take a break now?

If you will come this way...I’ll pay for the drinks.She will keep interrupting people.I’ll definitely work harder next term.Shall I give you a hand?

Absence of obligation – needn’t

Ability – can, could

She can speak 6 languages.Anybody who wants to can join the club.These roses can grow anywhere.When I was a baby I could put my foot in my mouth.You could get to my old school by bus, but not by train.

You needn’t work this Saturday.

Obligation, permission, etc. are usually seen from a speaker’s point of view in statements and the hearer’s point of view in questions.You must go and see Anne. (I think it is necessary)Must you go and see Anne? (Do you think it is necessary)You can borrow my car. (I give permission)Can I borrow you car? (Will you give me permission?)