Modals of Possibility: Could, May, Might, Can't

Show how sure you are about something.

Examples

• It might rain.
• That can't be true.

Key rules

• Could, may and might show possibility: It might rain
• Can't shows strong belief that something is impossible: That can't be true
• Use the base verb after each
• Use may not or might not for negative possibility (not can't)

Common mistakes

• It can rain → It might rain
• That mustn't be true → That can't be true