1. MODAL VERBS
A brief overview

2. Which verbs are MODAL VERBS?
can
could
will
would
may
might
shall
should
must
ought to

3. What do MODALS have in common?
We cannot use a to-infinitive after modals!
(I must to leave soon.)
Modals have the same form for all persons => no -s in the 3rd person singular.
(She cans dance very well.)
We cannot use two modals in one verb phrase.
(I will must take the exam again.)

4. What do MODALS have in common?
Modals cannot be put in different tenses like ordinary full verbs. They have no -ing form, we cannot form past tense with -ed, etc.
(He shoulded study more yesteday.)
Each modal verb has a basic meaning of its own. Other auxiliaries (be, do, have) have only grammatical function.

5. How to form questions and negatives?
Can I ...?
Could you ...?
Will he ...?
Would she ...?
May it ...?
Might we ...?
Shall I/Shall we ...?
Should they ...?
Must I ...?
Negatives
I cannot/can’t ...
I could not/couldn’t ...
He will not/won’t ...
I would not/wouldn’t ...
It may not ...
We might not/mightn’t ...
I/We shall not/shan’t ...
I should not/shouldn’t ...
I must not/mustn’t ...

6. Modals and related verbs used to talk about ABILITY: present and future
CAN/CANNOT
I can/cannot/can’t ride a bike.
Can you speak Japanese?
BE ABLE TO
He’d like to be able to dance.
Will you be able to come sooner?

7. Modals and related verbs used to talk about ABILITY: past
COULD/COULDN’T
I could/couldn’t sing very well when I was a child.
WAS/WERE ABLE TO
I was/wasn’t able to sing very well when I was a child.
Finally they were able to rescue her.
NOTE:
to talk about general ability in the past we use: COULD/COULDN’T/WAS ABLE TO
to talk about one specific action/achievement in the past we only use: WAS/WERE ABLE TO = managed to / succeed in

8. Modals and related verbs used to talk about PERMISSION:
CAN Can I stay up late?
COULD Could I stay up late?
MAY May I stay up late?
MIGHT Might I stay up late?
BE ALLOWED TO
You’re allowed to stay up late.

9. Modals and related verbs used to talk about PROHIBITION:
MUSTN’T You mustn’t smoke in here.
CAN’T You can’t smoke in here.
NOT BE ALLOWED TO You’re not allowed to smoke in here.
NOT BE PERMITTED TO You’re not permitted to smoke in here.
BE FORBIDDEN TO You’re forbidden to smoke in here.
BE PROHIBITED Smoking is prohibited.

10. Modals and related verbs used to talk about OBLIGATION:
MUST I must go to the dentist.
HAVE TO We have to change our shoes.
HAVE GOT TO We’ve got to change our shoes.
(used in everyday speech, more informal)
NEED TO I need to cut the grass.

11. Modals and related verbs used to talk about LACK OF OBLIGATION:
NEEDN’T He needn’t go there.
DON’T HAVE TO He doesn’t have to go there.
HAVEN’T GOT TO He hasn’t got to go there.
DON’T NEED TO He doesn’t need to go there.

12. Modals and related verbs used to talk about LACK OF OBLIGATION: past
NEEDN’T HAVE DONE
I needn’t have come. (I came, but it was not necessary. I didn’t know it was not necessary.)
DIDN’T NEED TO DO/DIDN’T HAVE TO DO
I didn’t need to/didn’t have to come. (I knew it was not necessary to come so I could decide whether to come or not to come. I had a choice.)

13. Modals used to talk about ADVISABILITY:
SHOULD/SHOULDN’T the weakest
You should/shouldn’t tell them everything.
OUGHT TO/OUGHT NOT TO
You ought to/ought not to tell them everything.
HAD BETTER/HAD BETTER NOT
You’d better/’d better not tell them everything. the strongest

14. Modals used to express CRITICISM and REGRET: past
SHOULD HAVE DONE
You should have studied more. (You were wrong not to do so.)
SHOULDN’T HAVE DONE
I shouldn’t have told him that secret. (I regret telling him.)
OUGHT TO HAVE DONE
She ought to have stopped drinking beer.
OUGHT NOT TO HAVE DONE
We ought not to have changed the colour of the room.

15. Modals and related verbs used to talk about CERTAINTY: present and future
MUST
He must be rich. (I’m sure he is rich.)
She must be waiting for him. (I’m sure she’s waiting for him right now.)
CAN’T
You can’t be hungry. (I’m sure you aren’t hungry.)
He can’t be listening. (I’m sure he isn’t listening now.)
BE BOUND TO
You’re bound to pass the exam. (I’m sure you will pass it.)

16. Modals used to talk about CERTAINTY: past
MUST
It must have been love.  (I’m certain it was love.)
He must have been waiting for you. (I’m sure he was waiting for you.)
CAN’T
He can’t have understood what I said. (I’m sure he didn’t.)
She can’t have been waiting for you. (I’m sure she wasn’t.)
COULDN’T
He couldn’t have understood what I said.
She couldn’t have been waiting for you.

17. Modals used to talk about POSSIBILITY: present and future
MAY/MAY NOT
Jack may not be in his office. (It’s probable he isn’t there.)
She may be thinking about him. (It’s possible she’s thinking about him now.)
MIGHT/MIGHT NOT
It might rain soon. (Perhaps it will rain soon.)
He might not be telling the truth. (Perhaps he isn’t doing so.)
COULD
They could have a car. (It’s possible they have it.)
She could still be working. (It’s probable she is working now.)

18. Modals used to talk about POSSIBILITY: past
MAY/MAY NOT
They may have got lost. (It’s probable they got lost.)
She may have been waiting long. (It’s possible she has/was.)
MIGHT/MIGHT NOT
She might not have known about it. (Perhaps she didn’t know about it.)
He might not have been telling the truth. (Perhaps he wasn’t.)
COULD
They could have left. (It’s possible they have left.)
She could have been driving fast. (It’s possible she was.)

19. WILL as a modal verb is used:
to talk about FUTURE opinions, beliefs, hopes, predictions (I’ll probably come later. I don’t think I’ll go out.)
to express offers, promises, requests, agreements, refusals (I won’t tell anybody. Will you shut the door, please?)
to express decisions made at the time of speaking (“Did you call Mom?” “I forgot. I’ll call her now.”)
in first conditional sentences (If she phones, I’ll tell you.)

20. WILL and SHALL WILL is used with all persons
I’ll/He’ll/She’ll come soon.
Will you get me that pill?
It probably won’t snow tomorrow.
We’ll/They’ll help you.
SHALL is used with I and we mainly to express suggestions.
Shall I close the door?
Shall we go to the theatre tonight?

21. WOULD as a modal verb is used:
in second and third conditional sentences (If I were you, I wouldn’t keep snakes. If she’d known him better, she would have been more careful.)
in reported speech (She said she wouldn’t tell me everything.)
to express polite offers and requests (Would you like something to drink? Would you pass me the salt, please?)
to talk about PAST habits, behaviour (When I was a child I would get up very early.)

22. References
ALEXANDER, L.G.: Longman English Grammar. New York: Longman, ISBN
MURPHY, R.: English Grammar In Use. Cambridge: Cambridge University Press, ISBN
VINCE, M. and EMMERSON, P.: Intermediate Language Practice with key. Oxford: Macmillan Publishers Limited, ISBN
VINCE, M. and EMMERSON, P.: First Certificate Language Practice with key. Oxford: Macmillan Publishers Limited, ISBN