1. Modal Auxiliaries Md. Shakhawat Hossain Lecturer, Dept. of English
Northern University Bangladesh

2. What does a modal do? A modal verb is also known as a helping verb.
It gives additional information about the main verb that follows it.
They indicate modality, or how something is done. There are nineteen main types of modals: can, could, may, might, shall, should, will, would, must, need, dare, ought to, have to, used to, be allowed to, be able to, be going to, had better, would rather etc.

3. The uses of ‘can’
1. Can (present or future) refers to a general ability to do something. Can is also used to refer to an ability to do something specific at a time in the future:
Ex: She can sing really well. I can come and see you next week.
2. Can is used to ask for permission (informal)
Ex: Can I use your pen, my friend? It is also possible to use ‘be( am, is, are )able to’ instead of ‘can’.

4. The uses of be allowed to
We use be allowed to when we ask what the rule is.
Ex: Am I allowed to drive a car without insurance?
Passengers are allowed to take one bag onto the plane.
Are they allowed to sit for the exam without admit cards?
For a general permission in the past we use either could or was/were allowed to.
Ex: I could always stay/I was always allowed to stay late as a child.

5. The uses of ‘could’
1. Could refers to a general past ability which was permanent. Ex: He could read when he was four. 2. Could is used to ask for permission in a polite way. Ex: Could I use your pen, my friend? 3. Could is used to say that something is possible. Ex: The story could be true, I suppose. (Possibly it is true.) 4. Sometimes could means only a small possibility. Ex: You could win a million pounds! (It is possible but not likely that you will win a million pounds.)

6. The uses of ‘could’ 5. Could is also used to make a suggestion.
Ex: We could go out for a walk around the lake.
Could + have + verb’s past participle form is used to say that someone had the chance or ability to do something in the past but he/she didn’t do it.
Ex: Hasan could have passed the exam. (but he didn’t take it)
Hamid could have bought a ticket while he waited for train. (but he didn’t)

7. The uses of be(was/were) able to
We use was/were able to to say that the ability or opportunity resulted in a particular action, something that really happened.
Ex: The drivers were able to stop (or managed to stop) before they crashed into each other.
In negative sentences and questions, we can use either form.
Ex: It was foggy, so the plane couldn’t/ wasn’t able to take off.

8. The uses of ‘may’ & ‘might’
1. May is used to ask for a formal permission.
Ex: May I go out, sir? May I come in, madam?
2. We use may or might to guess about the future say (something is possible or that it is quite likely). (We can use them for the present or the future.)
Ex: The sky is cloudy. It may /might rain today. (Perhaps it will rain today.)
There is a man over there. He may be /might be watching us. (Perhaps he is watching us.)
3. We use ‘might’ to express a possibility that is imagined. Ex: I wish I might be a president.

9. The uses of may not & might not
We use may not or might not / mightn’t to say that something negative is possible.
Ex: Jones may not get the job.
Tom might not be at home tomorrow.
I mightn’t finish the marathon tomorrow.
(It is possible that I will not finish it.)
I did not do very well in the examination. So I mightn’t/ may not stand first in the class.

10. The uses of can’t & couldn’t
We use can’t or couldn’t when we realize that something is impossible.
EX: We haven’t walked far. You can’t be tired yet.
Nick can’t be touring Scotland. I saw him here this morning.
Mike is completely unfit. He couldn’t run a marathon. (It is impossible for him to run it.)
Vicky is afraid of heights. She couldn’t climb onto the roof.

11. The uses of must
We use ‘must’ when we realize that something is certainly true.
Ex: Sheila isn’t answering the phone. She must be out.
He has just reached home and he is wet. So it must be raining out.
2. We use ‘must’ when the speaker feels that something is necessary.
You are weak in English. You must practice English regularly. (I’m telling you.)
3. I / we + must can also express a wish.
We must invite Claire. She’s wonderful company.

12. The use of have to
We use have to when the situation makes something necessary.
Ex: I have to exercise. (The doctor told me.)
We have to be quiet. (That’s the rule.)
We have to invite Trevor and Laura. They invited us last time.
Mark has to get the car repaired. There’s something wrong with the brakes.
That was not very good. We will have to do better next time.
Emma had to go to the dentist yesterday.

13. The uses of mustn’t & needn’t
We use mustn't to say that something is a bad idea.
Ex: You mustn’t drop those glasses. They’ll break.
I mustn’t forget my key, or I won’t get in.
We use needn’t when sth is not necessary.
Ex: You needn’t wash those glasses. They’re clean.
We can also use don’t have to and don’t need to when something is not necessary. The meaning is the same as needn’t.
Ex: You don’t have to / don’t need to wash those glasses. They’re clean.

14. The uses of didn’t need to & needn’t have
We use didn’t need to when something was not necessary.
Ex: Daniel hadn’t booked a seat, but luckily the train wasn’t full. He didn’t need to stand. (Standing was not necessary because there were seats.)
We use needn’t have + a past participle for something we did which we now know was not necessary.
Ex: Trevor and Laura booked a table for dinner. But the restaurant was empty. They needn’t have booked a table.

15. The uses of should, ought to, had better and be supposed to
We use should and ought to to say what is the best thing or the right thing to do. (obligation or duty, advisability & natural inference)
Ex: You should / ought to obey your parents.
He should be in Khulna now.
We use had better to say what is the best thing to do in a situation.
Ex: It’s cold. The children had better wear their coats.
We use be supposed to when we are talking about the normal or correct way of doing things.
Ex: The guests are supposed to buy flowers for the hostess.

16. Suggestions
Making a suggestion We can use Shall we …?, Let’s ….., Why don’t …..? or Subject + could …..to make a suggestion. Shall we go out for a walk? Let’s play a game of tennis. Why don’t we have a look around the market? We could watch a film on TV tonight. Asking for a suggestion To ask for a suggestion we use can, should or shall. Ex: Where shall/should we go out for a walk? What can I get Claire for her birthday?

17. Offers We can use will or can to offer to do something.
Ex: I will carry your bag. We can give you a lift.
We can also use question forms with shall or can.
Ex: Can I get a taxi for you?
Shall we pay you the money now?
To offer food or drink, we use would like.
Ex: Would you like to have a cup of coffee?
We can also use Will/Won’t you have……..?
Ex: Will you have a cup of tea?
Won’t you have something to drink?

18. Invitations
The words we use in invitations are similar to those we use in offers of food and drink. To invite someone, we often use Would you like to …..?
Ex: Would you like to have lunch with us?
We can also use Will/Won’t you……?
Ex: Will you join us for coffee?
Won’t you sit down?
In informal speech we can use the imperative.
Ex: Come and have coffee with us. Please sit down.