MODAL VERBS

General rules:

Modal verbs are always followed

by an infinitive:

• FOR PRESENT: by a present infinitive

She must go. (SIMPLE)

I must be going now. (CONT.)

• FOR PAST: by a perfect infinitive

He must have done that. (SIMPLE)

We must have been walking for

hours. (CONTINUOUS)

MODAL VERBS IN THE

PAST

2 ways of forming past tense:

modal verb is the same + infinitive is

changed (= perfect infinitive)

present: She could be at home now.

past: She could have been at home (when

you were looking for her.)

modal verb is changed + infinitive is the

same (present infinitive)

present: She must go to work every day.

past: She had to go to work every day.

OBLIGATION

(have to, must, should, ought to)

Put these sentences into past:

- I must go now.

- She has to listen to her.

- You should help him.

- I ought to do it.

Must and have to express obligation, should and ought to are used for giving advice.

Must have to. Must is more personal, formal, expresses the opinion of a speaker. Have to is normally based on a rule or law or on authority of another person

Should and ought to express mild obligation – they are used for giving advice. Ought to is very formal.

2. PERMISSION

( may, can, be allowed to)

Put these sentences into past:

- She may leave now.

- They are allowed to be here.

When asking for permission only the

present tense is used.

In the past the forms of be allowed to or

could are used.

The difference between can and may in

this sense is the same as in Slovene (ali

lahko grem / ali smem iti). May is more

formal.

3.PROBABILITY/ CERTAINTY

(will, must/can't, should, may,

might, could)

Put these sentences into past.

- This will be my sister at the door.

- He must be crazy. / She can’t be 40!

- They should be here soon.

- It might rain.

- They may go to Greece.

- You could be right.

All modal verbs expressing probability

form past by using the perfect infinitive.

Use a modal verb instead of MAYBE:

We may join you later.

Maybe we'll join you later. (It's not wrong

but the upper is much better.)

4. ABILITY

( can, to be able to)

Can for present, could for past. Other

forms are provided by be able to.

- I can speak English.

- I could speak English at the age of five.

- I'll be able to do it in a few years' time.

Compare:

- I could have helped him when he was

drowning. (I didn't!)

- I was able to help him when he was

drowning. (I did.)

5. REQUEST

( can, could, will, would)

Can/could/will/would you do me a favour?

6.WILLINGNESS AND REFUSAL

(will, won't, shall, wouldn't)

- I'll help you. (willingness)

- The car won't start. (refusal; meaning: thecar just refuses to start ☺)

- Shall I give you a hand? (offers; only withI/we)

- My mum said she wouldn't give me anymore money. Isn't she mean? (past)

Unfortunately, the same modal verb can

appear in different groups according to its

meaning and therefore form past tense in

both ways (but with a difference in

meaning).

Compare:

present: I must go now.

obligation:

past: I had to go yesterday.

MUST

present: She must be drunk now.

certainty:

past: She must have beendrunk when I saw her.

present: I can't swim.

lack of ability:

past: I couldn't swim when

I was 5.

CAN'Tpresent: That can't be

right.

certainty:

past: That can't have been

right.