may / might

The difference between may and might is very small:

Use may when the event is slightly more likely to happen:

  • “What are you doing this weekend?”

    “Shopping! I’m going to buy some new clothes, and I may get a new hat as well.” (it’s slightly more probable that I will buy the hat)

  • “What are you doing this weekend?”

    “I might go to the movies. I’m not sure.”

    (it’s slightly less probable that I will go to the movies)

    However, in this simple case, the words really are interchangeable; you can use either one.

    When making guesses about something that happened in the past, we usually use might + have + past participle.

  • “Why is Sheila so happy today?”

    “I don’t know. She might have gotten a promotion – I’d heard a rumor that the boss was thinking of making her a manager.”

    When asking permission, use may (or can/could):

  • “May I open the window?”

    This question is correct, but it sounds rather formal. Most English speakers would probably say “Can I open the window?” or “Could I open the window?”

    May not means “no permission”; might not means “maybe not.”

  • Students may not use cell phones during the exam.
  • I might not go to the wedding. or maybe I will go, but maybe I won’t go.