1. played
2. was playing
3. was playing
4. was playing
5. didn't play
6. wasn't playing
7. was cooking
8. was cooking
9. washed
10. were washing
11. did you do
12. were you doing
13. was sleeping
14. was sitting
15. was Nick doing
16. were you doing
17. wasn't sleeping
18. did he do - read
19. was he doing - was reading
20. was sleeping - was knitting