9. My sister helps me wash my clothes when I am busy.

→When I am busy, I often get my sister wash my clothes.

10. The manager usually asks his personal assistant to sort out his documents.

→ The manager usually has his personal assistant sort out his documents.

11. Everyone was surprised that the singer had very little money when he died.

→ The singer had very little money when he died which made everyone suprised.

12. I have forgotten that poet's name, but he is very well-known.

→That poet, whose name I have forgotten, is very well-known.

13. I work in the factory which has more than one thousand employees.

→There are more than one thousand employees work in my factory.

14. I'm only interested in why he did it.

→The only thing which I interested in is why he did it.

15. The football team have won all their matches this season, and their manager is a famous Spanish footballer.

→ The football team, whose manager is a famous Spanish footballer, have won all their matches in this season.

16. I spoke to Mr. and Mrs. Gibbs only last week just before they died in that terrible train accident.

→ Mr. and Mrs. Gibbs, whom I spoke to only last week, died in that terrible train accident.

17. Michael laughed when I told him the joke.

→The joke I told Michael made him laugh.

18. I know this reporter's background well and he is absolutely honest.

→ This reporter, whose background I know well, is absolutely honest.