Modal verbs (must, can't, may/might)
Change the sentences using modal verbs, then press "Check" to check your answers.
1. I’m sure she is at school.
2. I’m sure Susan has paid the bill.
3. Perhaps he was ill.
4. It’s impossible that they missed the plane.
5. I’m certain he isn't working at the library.
at the library.
6. I’m sure she knows him well.
7. Perhaps they went home.
8. It’s impossible that he’s telling the truth.
9. It is possible that he’s working late tonight.
10. Perhaps they have missed the bus.
11. I’m certain he was sleeping.
12. Perhaps she has been lying.
13. It’s impossible that she saw us.
14. I’m sure they are studying.
15. It is possible that she has finished her work.