1. No, I am not.
2. Yes, I am.
3. I am a student.
4. Yes, he is.
5. Yes, he is/No, he isn't .
6. My friend is a doctor/teacher.
7. No, I am not. или Yes, I am.
8. No, I am not. или Yes, I am.
9. No, I am not. или Yes, I am.
10. You are a doctor/teacher.
11. Yes, he is./No, he isn't.
12. Yes, they are./No, they aren't.
13. Yes, we are.
14. Yes, he is.
15. Nick is a doctor.
16. Nick is a good doctor.
17. Nick is a doctor.