DIFFERENCES BETWEEN MAY AND MIGHT

May and might are both ways of expressing possibility. Is there a difference between the ways in which they should be used?

 Some people insist that you should use May (present tense) when talking about a current situation and might (past tense) when talking about an event that happened in the past.

 For example:

·         I may go home early if I’m tired. (present tense)

·         He might have visited Italy before settling in Nuremberg. (past tense)

In practice, this distinction is rarely made today and the two words are generally interchangeable:

·         I might go home early if I’m tired.

·         He may have visited Italy before settling in Nuremberg.

But there is a distinction between may have and might have in certain contexts. If the truth of a situation is still not known at the time of speaking or writing, either of the two is acceptable:

• ·         By the time you read this, he may have made his decision.
• ·         I think that comment might have offended some people.

 If the event or situation referred to did not in fact occur, it's better to use might have:

·         The draw against Italy might have been a turning point, but it didn't turn out like that.

http://www.oxforddictionaries.com/words/may-or-might