May and might both talk about possibility, but they are not always interchangeable.
Use may for permission and for a possibility that feels fairly real. For example, You may leave early gives permission. In a possibility sentence, We may see delays this afternoon suggests something could realistically happen.
Use might for a possibility that feels less certain, more hypothetical, or more tentative. For example, It might rain later sounds a little less confident than It may rain later.
- May: permission, or a more direct sense of possibility
- Might: weaker possibility, hypothetical meaning, or extra caution
In modern English, both words can sometimes express possibility, so context matters. Still, if you want to sound more tentative, might is often the better choice. If you want to grant permission, use may.