A modal verb is a verb that is used before another verb to express meanings such as
ability, permission, possibility, necessity or advice.
The modal verbs are can, could,may, might,must, ought, shall, should, will and
would. Need and used to can follow some of the grammar patterns of modal verbs,
but are also used like ordinary verbs. For more information about any modal verb,
look in the dictionary at the entry for the word.
The grammar of modal verbs
• they are usually followed by an infinitive without to
You should thank him
• there is no ‘s’ for the third person singular
he must, she must, it must
• they have no infinitive or -ing form
• they cannot follow another verb.
• they are not used in future, perfect or continuous tenses
Example modal verb: can
Look at the extract on the right
which is based on what is in the
dictionary. From the guidewords,we
can see that the modal verb can is
used to describe the following ideas:
• ability
• permission
• request
• possibility
• polite offers of help
Look at the example sentences.
Notice that
• The forms of can for you and she
are the same: you can, she can
• When you use modal verbs in
questions or negatives you do not
use auxiliary verbs such as do or
have: Can you drive?
can (ABILITY) modal verb
to be able to
Can you drive?
She can speak four languages.
can (PERMISSION) modal verb
INFORMAL to be allowed to, either by general
or personal permission
You can park over there.
You can have a piece of cake if you eat your
vegetables!
can (REQUEST) modal verb
INFORMAL used informally to request something
If you see Adrian, can you tell him (= please tell
him) I’m in London next weekend?
can (POSSIBILITY) modal verb
used to express possibility in the present,
although not in the future
You can get stamps from the local newsagents.
can (OFFER) modal verb
used in polite offers of help
Can I help you with those bags?
source : Cambridge Advanced Learner's Dictionary, 3rd edition
© Cambridge University Press 2008
