Choose the correct alternative.

1. I'm afraid I couldn't / shouldn't find it. Sorry.

   1.   ?    couldn't
   2.   ?    shouldn't

2. What would / ought you have done in my position?

   1. would
   2. ought
   Check

3. He can't / mustn't have seen us.

   1. mustn't
   2. can't
   Check

4. Surely he would / must have come over and talked to us if he had.

   1. would
   2. must
   Check

5. They must / could have been so worried about her.

   1. must
   2. could
   Check

6. You really mustn't / shouldn't have done that.

   1. shouldn't
   2. mustn't
   Check

7. It can / might have been him, but I can't say for sure.

   1. might
   2. can
   Check

8. You could / would have told me! Why didn't you?

   1. could
   2. would
   Check

9. It simply must / should have been him.

   1. must
   2. should
   Check

10. Those guys in the pub could / should have stolen my purse. They looked very suspicious.

    1. could
    2. should
    Check