May vs Might

  The difference between the modal auxiliary verbs "may" and "might" can be confusing for many English learners. It's time to break down one more barrier in your journey to improve your grammar and become a better English speaker.
  Let's get started without further ado.

may and might express possibility

  May and might express possibility. It is not a guarantee, just a possibility and there are degrees of possibility.

  Even though many native speakers may disagree on certainty; "may" is used for higher probability(indicating that something is likely to happen) and "might" is used for less probability(indicating that there is a chance but not as high as "may" suggests).

I may go to Italy next summer.

  I'm seriously thinking about going to Italy, have done my research and am trying to make it happen.

I might go to Italy next summer.

  There is a chance for that trip to happen, it is just one of the options, I'll see.

structures and examples

positive | present and future

  subject + may + infinitive (first form of the verb)
  subject + might + infinitive

She might be the one.

negative | present and future

  subject + may + not + infinitive (first form of the verb)
  subject + might + not + infinitive

She may not be the one.

question | present and future

  may + subject + infinitive (first form of the verb)
  might + subject + infinitive

Might she be the one?

positive | past

  subject + may + have + past participle (third form of the verb)
  subject + might + have + past participle

I might have ruined my whole career yesterday, with that interview.

negative | past

  subject + may + not + have + past participle (third form of the verb)
  subject + might + not + have + past participle

He looks tense. He may not have finished his homework.

question | past

  may + subject + have + past participle (third form of the verb)
  might + subject + have + past participle

Might they have arrived before us?

  may have = may've
  might have = might've

may with permission

  We can also use may for asking and giving permission politely.

  May I bring my little puppy friend inside?
  Of course sweetheart, you may bring her in.

Conclusion

  Hope this will help you use may and might more wisely. You may become a great English speaker one day, if you study enough.