Grammar Reference

Modal verbs

What are they?

Modal auxiliary verbs are can, could, may, might, shall, should, will, would, must and ought to.

They are used before other verbs to add meaning, like certainty or obligation, to these verbs.

Review of modal verbs:

Affirmative

I
You
He
She
We
They

can
could
may
might
shall
should
will
would
must
ought to
visit

Negative

I
You
He
She
We
They

can't
couldn't
mightn't
may not
shall not
shouldn't
won't
wouldn't
mustn't
*oughtn't to
visit

*Ought to is not normally used in negative sentences.

Question

Can
Could
May
Might
Shall
Should
Will
Would
Must

I/you/he/she
we/they
visit?
Ought I/you/he/she
we/they
to visit?

Modal verbs can be used:

Possibility

Certainty

Ability

Requests

Advice

Future

Obligation

Prohibition

Permission

Deduction

Modal verbs are followed by the base form of a verb (except ought, which is followed by to).

Do not add an -s to a modal verb in the third person singular.

Modal verbs do not need the auxiliary do in the negative and question forms.