15. I wish we understood them.
16. I wish I weren't late for school.
17. I wish the bus hadn't been late today.
18. I wish she liked this place.
19. I wish these students didn't talk too much in class.
20. I wish I could play basketball.

15. We didn’t understand them.
   - I wish we had understood them.

16. I will be late for school.
   - I wish I wouldn’t be late for school.

17. The bus was late today.
   - I wish the bus hadn’t been late today.

18. She doesn’t like this place.
   - I wish she liked this place.

19. These students talked too much in class.
   - I wish these students hadn’t talked too much in class.

20. I can’t play basketball.
   - I wish I could play basketball.