2, He ought to be more careful ( ought to : nên )

3, that must be John's car ( must : chắc là )

4, he can't be her brother ( can't: không thể)

5, he wasn't able to swim when he was five ( be able to = can/ could : có thể)

6, he might win the race ( it's possible + that + S = S + might )

7, you musn't play in their garden ( musn't = be not allowed : không được )

8, they didn't need to repair the car ( didn't need = be not neccesary : không cần thiết)

9, Would you like me to pour another drink (?)

10, you can't eat so much ( it's not possible = can't )

11, Shall I open the door?

12, she could be still at work ( it's possible = could)

13, would you like me to help you with that?

14, she can't be the woman who spoke to me ( I don't think = can't; tùy ngữ cảnh)

15, we needn't go shopping with Mum ( don't have to = needn't : không cần phải)

16, she can be 50 years old ( it is possible = can )

17, you had better tell him the truth ( had better = it would be a good idea )

18, you should study harder ( should : nên)