1. Where is Mike ? Maybe he forgot= He might have forgotten 2. Where is Susan? P robably she overslept= She might have overslept 3. I lost my money. I am sure I lost it at work= I must have lost it at work 4. You didn't see Mike. I am sure of it. He is in Canada. You can't have seen Mike. 5. Probably she didn't cheat. She might not have cheated. 6. It is a pity you didn't visit me. You could have visited me. ( regret) 7. We have a lot of bread. It was not necessary o f you to buy it. You needn't have bought it. 8. You didn't clean your house. You should have cleaned your house. !!! I had to work a lot. I could swim when I was five.