Active: She was writing a novel.

Passive: A novel was being written by her.

Active: She was not preparing dinner.

Passive: Dinner was not being prepared by her.

Active: Were they reading a book?

Passive: Was a book being read by them? 

Change the following into passive voice.

1. He was playing the guitar.
2. The children were making a noise.
3. The mechanics were repairing the car.
4. She was drawing a beautiful picture.
5. The girls were playing a football match.
6. He was answering the question.
7. She was teaching him.
8. He was not feeding the dogs.
9. We were not painting the gate.
10. The boys were not learning their lessons.
11. The peon was not ringing the bell.
12. They were not starting Generator.  
13. They were not implementing rules.
14. He was not cooking French fries.
15. Was he singing a song?
16. Was she cleaning her room?
17. Were they playing computer game?
18. Was my mother not washing the dishes?
19. Was she not writing an application?
20. Was he cheating you?