1.She didn't have to wear a uniform.
2.It's Sunday - we don't have to go to school.
3.He had to pay a fine.
4.He's carrying a bag full of letters - He may be a postman.
5.Who's that at the door? - It can't be Paula because she's at work.
6.He doesn't like confined spaces - He must have claustrophobia.
7.He might arrive late.