Ответ:

1. can't

2. Can

3. can

4. can't

5. could

6. play

7. Could

8. could

9. couldn't

1) She can't sing

2) Can they sing

3) Yes, they can

4) No, they can't

5) He could dance

6) We couldn't play tennis

7) Could you speak German?

8) Yes, i could

9) No, i couldn't