Exercise 4

Rewrite the sentences using must, can't or may.

1. I'm sure he isn't at home.
2. I'm sure he is at work.
3. Perhaps he is preparing for a meeting.
4. I'm sure he isn't on a break.
5. I'm sure she's a student.
6. Perhaps she is in the library.
7. Perhaps she is doing research for a project.
8. I'm sure she has been working hard.