Modal verbs: general notes
MODALS 1
Modal verb(e.g can, could, may, might, must, shall, should, will,
would) are special auxiliary which add to the meaning of other
verbs. They follow these rules:
+ modal verbs never change (we don’t add –s or –ed or –ing to
them): He might help.
! We don’t put to before the second verb: I can help (not I can to
help).
- Not follows the modal verb: That will not (won’t) be
? The modal verb goes first: Could you sweep the floor?
! Ought is like other modal verbs but we put to after it:
I/you/he/we/they ought to help (not they ought help.)
MAKING SUGGESTIONS AND OFFERS
To make a suggestion: Shall…?
(I) can….
Less sure of what we are suggesting, (We) could…
*We can also use: Why don’t/ What about/ How about
When we offer to do something, we usually use shall: Shall I…
ASKING FOR, GIVING AND REFUSING PERMISSION
When we give permission or talk about having permission, we
use can:
Less polite: Can I…?
More polite: Could/May I…?
Answer: Yes, of course/Certainly(etc.)
Answer: I’m afraid not/Sorry (etc.)
When we refuse permission, we use can’t
MODALS 2
OBLIGATION – must and have to
Must and have to = it is essential or necessary.
Must is a modal verb.
Have to isn’t a modal verb.
Although must and have to have similar meanings, mustn’t =
don’t have to.
NECESSITY – need
Need = it is necessary
Need is a normal verb.
In the negative need can be either a modal verb: You needn’t
worry. Or a normal verb: You don’t need to worry.
Needn’t and don’t need to = it isn’t necessary = don’t have to.
ORDERS AND ADVICE – should, must, ought to and could to give
advice.
Strong advice
Less strong advice
You must check the details. You should/ought to take a diary. You could take some books.
In the negative, we use shouldn’t or ought not to.
*We don’t use couldn’t to give advice.
*We use should and ought to when we are talking about the right
thing to do.
MODALS 3
CERTAINTY AND POSSIBILITY
When we’re sure something is true, we use must.
When we think something is possible, we use might/could/may.
When we’re sure something isn’t true we use can’t.
We also use might/could/may when we are uncertain about the
future.
ABILITY (I CAN…, I’M ABLE TO…, I COULD…)
I can = I know how to do something or it is possible for me to do
something.
In the present we use can (a modal verb) or be able to (not a
modal verb).
Be able to is less common.
In the past we use could or was able to.
For all other forms, we use be able to:
Future: will be able to…
Present perfect: hasn’t been able to….
Infinitive: to be able to…