MAY:
Утвердительное: She may go to the party tonight if she finishes her work on time.
Вопросительное: May I borrow your car for the weekend?
Отрицательное: You may not leave the house without completing your chores.

MUST:
Утвердительное: We must finish this project by the end of the day.
Вопросительное: Must we attend the meeting tomorrow morning?
Отрицательное: You must not forget to set your alarm clock for the morning.

MIGHT:
Утвердительное: It might rain later, so you should bring an umbrella.
Вопросительное: Might you be interested in joining us for dinner tonight?
Отрицательное: He might not be able to make it to the game due to his prior commitments.