1 must
2 was able
3 have to
4 must
5 should
6 have
7 might
8 mustn't
9 need to
10 had to
1. Must
2. Couldn't
3. Must
4. Should
5. Should
6. Ought
7. May
8. Mustn't
9. Should/need to
10. Should have
1 must
2 was able
3 have to
4 must
5 should
6 have
7 might
8 mustn't
9 need to
10 had to
1. Must
2. Couldn't
3. Must
4. Should
5. Should
6. Ought
7. May
8. Mustn't
9. Should/need to
10. Should have