1) had, would go

2) had known, would have gone

3) had missed, would have been

4) knew, would help

5) had forgotten, wouldn't have reminded

6) had had, would have sent

7) knew, would phone

8) would have enjoyed, had been

9) would have been, had walked

10) was, would go

11) had been, would have eaten

12) had got, wouldn't have had

13) would have lost, had sold

14) were, could

15) had asked, would have told

16) had been, wouldn't have played

17) was, wouldn't have

18) hadn't contacted, wouldn't have caught

19) didn't feel, wouldn't smoke

20) had called, would have told