UK:*UK and possibly other pronunciationsUK and possibly other pronunciations'May', 'may': /ˈmeɪ/US:USA pronunciation: IPA and respellingUSA pronuncation: IPA/meɪ/ ,USA pronunciation: respelling'May', 'may': (mā)

Inflections of 'may' (v): (⇒ conjugate)
v aux present
v aux past
WordReference Collins English Usage © 2020
might - may
Might and may are used mainly to talk about possibility. They can also be used to make a request, to ask permission, or to make a suggestion. When might and may are used with the same meaning, may is more formal than might. Might and may are called modals.
In conversation, the negative form mightn't is often used instead of ‘might not’. The form mayn't is much less common. People usually use the full form may not.
He mightn't have time to see you.
It may not be as hard as you think.
possibility: the present and the future
You can use might or may to say that it is possible that something is true or that something will happen in the future.
I might see you at the party.
This may be why she enjoys her work.
You can use could in a similar way, but only in positive sentences.
Don't eat it. It could be poisonous.
You can use might well or may well to show that it is fairly likely that something is true.
You might well be right.
I think that may well be the last time we see him.
You use might not or may not to say that it is possible that something is not true.
He might not like spicy food.
That may not be the reason she left.
Be careful
Don't use ‘might not’ or ‘may not’ to say that it is impossible that something is true. Instead you use could not, cannot, or can't.
She could not have known what happened unless she was there.
He cannot be younger than me.
You can't talk to the dead.
Be careful
Don't use ‘may’ when you are asking if something is possible. Don't say, for example, ‘May he be right?’ Say ‘Might he be right?’ or, more usually, ‘Could he be right?’
Might we have got the date wrong?
Could this be true?
Be careful
Don't say ‘What may happen?’ You usually say ‘What is likely to happen?’
What are likely to be the effects of these changes?
possibility: the past
You use might or may with have to say that it is possible that something happened in the past, but you do not know whether it happened or not.
Jorge didn't play well. He might have been feeling tired.
I may have been a little unfair to you.
Could have can be used in a similar way.
It could have been one of the staff that stole the money.
Be careful
However, if something did not happen and you want to say that there was a possibility of it happening, you can only use might have or could have. Don't use ‘may have’. For example, you say ‘If he hadn’t fallen, he might have won the race'. Don't say ‘If he hadn’t hurt his ankle, he may have won the race'.
A lot of men died who might have been saved.
You use might not or may not with have to say that it is possible that something did not happen or was not true.
They might not have got your message.
Her parents may not have realized what she was doing.
Be careful
Don't use ‘might not have’ or ‘may not have’ to say that it is impossible that something happened or was true. Instead you use could not have or, in British English, cannot have.
They could not have guessed what was going to happen.
The measurement can't have been wrong.
requests and permission
In formal English, may and might are sometimes used for making a request, or asking or giving permission.
Might I ask a question?
You may leave the table.
Requests, orders, and instructions Permission
Might is often used in polite suggestions.
You might like to read this and see what you think.
I think it might be better to switch off your phones.
'may' also found in these entries:

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