1) You really have to work harder if you want to pass that examination.
2) Many children in Britian have to wear uniform when they go to school.
3) Last night Don suddenly became ill. We must call the doctor.
4) I can stay in bed tomorrow morning because I don't have to work.
5) What ever you do, you mustn't touch that switch. It's very dangerous.
6) Ann has had to wear glasses since she was eight years old.
7) I'm afraid I can't come tomorrow. I will have to work late.
8) I'm sorry I couldn't come yesterday. I had to work late.
9) You mustn't forget what I told you. It's very important .
10) Tom may have to go away next week.
11) We couldn't repair the car ourselves. We must take it to the garage.
12) She don't have to get up so early. She gets up early because she prefers to.
13) We haven't had to leave yet. We've got plenty of time .
14) When you come to London again, you must come and see us.
15) I don't want anyone to know. You mustn't tell anyone what I said .