1. can, should
2. might
3. must
4. can
5. has to
6. can't
7. could
8. mustn't
9. had to
10. needn't
11. mustn't
12. needn't
13. cannot
14. mustn't
15. had to
16. could
17. shouldn't
18. should
19. ought not to
20. should
21. may
22. should
23. mustn't
24. shouldn't