1. Is your (my) friend a worker? My friend isn't a worker.
2. Are they policemen? They aren't policemen.
3. Is your (my) father an engineer? My father isn't an engineer.
4. Is his sister 18? His sister isn't 18.
5. Are your (my) parents pensioners? My parents aren't pensioners.
6. Are you (we) students? We aren't students.
7. Is it cold today? It isn't cold today.
8. Are you busy on Friday? (Am I busy on Friday?) I'm not busy on Friday.
9. Is he 45? He isn't 45.
10. Is Mr. Black a policeman? Mr. Black isn't policeman.