3. No,they couldn't
4. Yes,it can
5. Yes,she can
6. No, I can't
7. No,he couldn't
8. Yes,they could
9. Yes, he can
10. Yes, she could
11. No,she can't
12. Yes,it can
13. Yes,she can
14. Yes,they could
15. No,we can't
16. No,they can't
17. No,they couldn't
18. No,we can't
19. Yes,he could