1. will be able

2. can’t

3. couldn’t / wasn’t able to

4. have to

5. might / could / must

6. didn’t have to

7. weren’t allowed

8. have to

9. must / have to

10. shouldn’t

11. can / are able to

12. be allowed

13. was able

14. mustn’t

15. may / could

16. mustn’t

17. weren’t able to / couldn’t

18. shouldn’t

19. don’t have / don’t need / need / have

20. must