1. Mary types letters in the office.

=> Letters are typed in the office by Mary.
2. His father will help you tomorrow.

=> You’ll be helped by his father tomorrow.

3. Science and technology have completely changed human life.

=> The human life has completely been changed with science and technology.

4. Peter broke this bottle.

=> This bottle was broken by Peter.

5. They are learning English in the room.

=> English is being learnt in the room.

6. Nothing can change my mind.

=> My mind can’t be changed.

7. No one had told me about it.

=> I hadn’t been told about it.

8. I don’t know her telephone number

=> Her telephone number isn’t known.

9. My students will bring the children home.

=> The children will be brought home by my students.
10. They sent me a present last week.

=> I was sent a present last week.

11. She gave us more information.

=> We were given more information.

12. The chief engineer was instructing all the workers of the plan.

=> All the workers of the plan were being instructed by the chief engineer.
13. They can’t make tea with cold water.

=> Tea can’t be made with cold water.

14. Somebody has taken some of my books away.

=> Some of my books have been taken away.
15. They will hold the meeting before May Day.

=> The meeting will be held before May Day.

16. They have to repair the engine of the car.

=> The engine of the car has to be repaired.
17. The boys broke the window and took away some pictures.

=> The window was broken and some pictures were taken away by the boys.
18. People spend a lot of money on advertising every day.

=> A lot of money is spent on advertising every day.
19. Teacher is going to tell a story.

=> A story is going to be told by teacher.
20. Mary is cutting a cake with a sharp knife.

=> A cake is being cut with a sharp knife by Mary.
21. The children looked at the woman with a red hat.

=> The woman with a red hat was looked at by the children.

22. They have provided the victims with food and clothing.

=> The victims have been provided with food and clothing.
23. People speak English in almost every corner of the world.

=> English is spoken in almost every corner of the world.
24. You mustn’t use this machine after 5:30 p.m.

=> This machine mustn’t be used after 5:30 p.m.
25. After class, one of the students always erases the chalk board.

=> After class, the chalk board is always erased by one of the students.