Rewrite these sentences using the correct modal verb construction.

1. It's possible that this man is a thief. This man might / could / may be a thief.
2. It's possible that you're right. 
3. Perhaps he rang but you were out. 
4. I'm sure you're absolutely exhausted. 
5. You aren't serious, are you? 
6. It wasn't John. He was in London then. 
7. I'm sure he lied and that's why he's got the job. 
8. I'm sure she didn't come only because she forgot about the meeting. 
9. It wasn't possible for me to see him then because I was somewhere else. 
10. She's probably in love - she looks so different.