1. Nobody helped Thanh repair the bike. => Thanh repaired the bike by himself
2. Putting a knife into an electrical socket is dangerous. => It is dangerous to put a knife into an electrical socket
3. It isn't necessary for you to set off early. => You don't have to set off early
4. Would you like me to call Linh? => I'll call Linh if you like
5. I had a cat once, but I don't any more. => I used to have a cat
6. We started living here fifteen years ago. => We have lived here for 15 years
7. I last wrote to my uncle in July. => I haven't written to my uncle since July
8. It is a long time since we became close friends. => We have become close friends for a long time ago
9. Tam doesn't type as fast as she used to. => Tam used to type faster than she does now
10. Nhung will be fifteen years old next week. => It is Nhung's 15th birthday next week