The Modals in English Grammar
- A) Can and Could as ‘Possibility’ & ‘Ability’.
The most important meaning of Can and Could is ‘to be
He can walk thirty Miles a day.
We can play tennis.
She cannot play tennis.
When she was young, she could swim across the lake.
- B) Can and Could as Permission:
Ravindra can’t smoke here, but he can smoke in the garden.
Ravi could I leave right now.
- C) Can/could be used in polite requests, orders & suggestions.
Can she make a cup of coffee, please?
Can you come here a minute.
Could you please tell me how to get to Main Street?
- D) Could and Can be used in sentences expressing wishes.
I wish I could visit Delhi.
I wish I could have helped you.
- E) Could and Can be used in either the main clause or the
subordinate clause of a statement expressing a false or
If he were a stronger, he could help us push the car out
of the snow.
She could have caught the bus if she had left in time.
I would be glad if I could help you.
- F) In informal English, Can is often used with the meaning to be allowed to.
He says I can take the day off.
Can I have some more soup?
Note: may in such situations is more correct.
He says I may take the day off.
Normally, we use can when we make present decisions
about future ability.
Can you help me with my homework? (Present)
We are busy today. But we can help you tomorrow. (Future)
Could + have + past participle
When the speaker had the opportunity to do something, but you are not sure he did it. You can also use it when the action was possible but you are not sure if it really happened.
After dinner, I felt really sick. It could have been the fish. It tasted a little strange.
MAY and MIGHT
MAY is used to express possibility:
It may rain today.
It might rain today.
May, Might: to be allowed to.
The members of the organization agree that I may join it.
The members of the organization agreed that I might join it.
The auxiliary must is a stronger form of May and Might.
You must provide proper identification in order to cash a
They must work harder if they are to succeed.
- c) It should be noted that the meaning of ‘Must not’ is to be obliged not to.
You must not leave.
He must not speak.
In order to express the idea of not being obliged to do
something, an expression such as not to be obliged to or
not to have to is generally used.
You do not have to leave. =You may stay, if you wish
He is not obliged to speak. =He may be silent, if he wishes.
Note: The auxiliaries Could, Might can be used
To express differing degrees
Raj might have taken the money, but it seems unlikely.
It is possible he may have called while we were out.
It must have rained last night, because the streets are wet.
- d) Thus, Might expresses the highest degree of politeness.
Might I observe what you are doing?
Might I offer some advice?
- e) May, Might and Must used to express probability:
somewhat probable: may, might
highly probable: must
He must be mistaken.
You might be right.
It may snow later this afternoon
- f) May, Might and Must used to express Affirmative:
Eg. She may go to the cinema.
They might go to the cinema.
She may not go to the cinema.
They might not go to the cinema.
Must (subjective obligation): Often use must to say that
something is essential or necessary,
Note: Like all auxiliary verbs, must, CANNOT be followed
by ‘to’. So, we say: I must go now.
I must go home.
You must visit us.
Must express personal obligation.
It is sometimes possible to use ‘must’ for strong obligation,
But generally we use ‘have to’ for this.
Eg. I must stop smoking.
He must work harder.
Must express degrees of certainty
She must have gone to the party.
Can use ‘Must’ to talk about Present or Future.
Eg. I must go now. (present)
I must call my mother tomorrow. (future)
Visitors must not smoke. (present)
I mustn’t forget Tara’s birthday. (future)
Must not/Mustn’t: We use must not to say that
something is not permitted or allowed, for example:
Eg. I mustn’t forget my keys.
Students must not be late.
I mustn’t eat so much sugar. (subjective)
You mustn’t watch so much television. (subjective)
Students must not leave bicycles here. (objective)
Policemen must not drink on duty. (objective)
The Modals in English Grammar
Perfect Modals are used to talk about the past and what was advisable in the past.
Modal + have + past participle
I should have cooked more burgers. Now we don’t have enough.
Sam must have gone to the beach yesterday. He has a sunburn today.
She might have left her keys on the table, but she’s not sure.
They could have driven their car, but they decided to walk instead.
Must + have + past participle
When you are almost certain that the action happened. Based on facts or current situation, you conclude that the action happened.
Ravi looks really tired today. He must have gone to bed late last night.
Might + have + past participle
When the action was possible, but you are not sure it happened- the same meaning as
may have, could have + past participle