1. INTERMEDIATE CLASS MODALS IN PAST

2.  Certainty e.g. I can't have lost my keys! (I'm sure I didn't) Can't have

3.  Permission e.g. When I was a teenager, I could go out as late as I wanted.  General ability e.g. Tom could walk by the age of 8 months. Could

4.  Possibility, but did not happen e.g. I could have passed my driving test if I'd really tried.  Uncertainty e.g. I guess it could have been Sandra on the phone. Could have

5.  Permission e.g. When I was a teenager, I couldn't stay out as late as I wanted.  General ability e.g. I couldn't walk until I was 2.  Ability in a particular situation e.g. I tried hard but I couldn't persuade him to go to the party with us. Couldn't

6.  Possibility/ability e.g. I couldn't possibly have passed my driving test, even if I'd tried harder.  Uncertainty e.g. It couldn't have been Sandra on the phone, could it?  With comparative adjectives e.g. I couldn't have asked for better weather on my wedding day.  Unwillingness e.g. I couldn't have left the dog in the car for long (so I didn't). Couldn't have

7.  unnecessary action not done e.g. As I was alone this weekend, I didn't need to do any cooking (so I didn't). Didn’t need to

8.  Uncertainty e.g. I guess I may have been a bit hard on her when she came home an hour late. May have

9.  Obligation (past form of must) e.g. I couldn't go out last night because I had to do my homework. Had to

10.  Uncertainty e.g. He may not have found out yet that he has passed the test. May not have

11.  Possibility (didn't happen) e.g. You might have been killed!  Uncertainty e.g. I guess I might have been a bit hard on her when she came home an hour late.  Annoyance at someone's failure to do something e.g. You might have told me that you had invited all your colleagues round for dinner!  Might have known + would (idiom to ironically express that somebody's action was typical) e.g. I might have known that he would finish with me as soon as he found out I wasn't wealthy! Might have

12.  Uncertainty e.g. He may not have found out yet that he has passed the test. Might not have

13.  Certainty e.g. He must have known how much it was going to cost. (I'm sure he knew.)  With surely in exclamations e.g. Surely he must have known how much it was going to cost! Must have

14.  Criticism (more common is shouldn't have) e.g. You ought not to have been so frank with him. Ought not to have

15.  Expectation (should have is more common) e.g. Why is she late? She ought to have arrived by now! Ought to have

16.  Unnecessary action that was actually done e.g. Oh, you needn't have done the washing up! Needn't have

17.  Expectation e.g. Why is she late? She should have arrived by now!  Should have + verbs of thinking e.g. I should have thought you knew.  With be and adjectives, describing chance e.g. It was weird that you should have been staying in the same hostel last month.  Criticism (you didn't do something, but it would have been the right thing to do) e.g. The party was such fun last night! You should have come! Should have

18.  Criticism e.g. You shouldn't have been so frank with him.  Polite expression of thanks on receiving a gift or favour. e.g. "Here's a bottle of wine for you" "Oh, you really shouldn't have!" Shouldn't have

19.  unwillingness e.g. I asked Tom to close the window, but he wouldn't do it. Would not

20.  Events in the past that did not happen e.g. I wouldn't have gone out with him, but he didn't ask me.  Assumptions e.g. Oh, that would have been Sarah on the phone just now. Would have