can, could, may, might
(can, could, may, might)
1. In a statement, we use can, could, may or might in this way:
Subject + can, could, may or might + base form of main verb / the verb ‘to be’
Example: You may take a week’s leave.
Hoe Boon might be the next head prefect.
2. In a question, we use can, could, may or might at the beginning in this way:
Can, could, May or might + Subject + base form of main verb / the verb ‘to be’
Example: Can animals think?
Could you be more patient with him?
3. We use could and might to express the possibility of an action in the past in this way:
Subject + could / might + have + past participle form of main verb / the verb ‘to be’
The thief could have taken my wallet when we were in the bus.
Someone on the bus might have seen the person who took my wallet.
Can and could are used to ask for permission and make requests for help.
(Could is considered more polite than can)
Can / could I practice a tune on your piano?
Can / could you pass me the salt and pepper?
May / might are used to ask for permission in a more formal manner.
(Might is used to show that the speaker is more hesitant or unsure.)
May I speak to Mr Tan Lee Kim?
Might I borrow your new camera?
Usually may (not might) is used to give permission
You may borrow my camera if you’ll take good care of it.
Can, could and may are used when we offer to do something for another person.
Can / could / may I get you something to drink?
Can and May are used to express present and future possibility.
(May is usually used to refer to a less likely possibility than can)
We can hold a farewell party for her this Saturday.
We may hold a farewell party for her this Saturday.
Could is used instead of can to that the speaker is more hesitant or unsure.
Might is used instead of May to indicate a less likely possibility.
Can is also used to refer to the ability to do something.
Nowadays, many young children can use computer.
Could is used as the past tense of can to refer to the ability to do something in the past.