May and might are modal verbs. Lesson 27 shows you how to make correct sentences with them. This lesson shows you when to use them.
EXAMPLE: I don't know where John is but he might be helping Peter.
NOTICE: The Canadian winter may be very cold. = this winter
BUT: The Canadian winter can be very cold. = generally
EXAMPLE: Gas prices might fall again soon.
NOTICE: also may
EXAMPLE: I think you may have caught a cold.
NOTICE: also might; also could (Lesson 29)
EXAMPLE: Visitors may enter the museum from 9:00 to 5:00 each day.
May I come in?
May we think about it for a few days?
We use might (NOT may) in sentences with a past tense verb before the modal (Lesson 63).
I thought the road might be blocked so I went another way.
He told me that the next winter in Canada might be very cold.