Dùngđộngtừtrợthíchhợp, chuyểncáccâusau sang câuphủđịnh (-) vàcâuhỏi (?) Examples: 1. The children are playing marbles. (-) The children aren’t playing marbles. (?) Are the children playing marbles? 2. My teacher lives in Hong Son (-) My teacher doesn’t live in Hong Son (?) Does your teacher live in Hong Son? 3. Nam’s reading books at the moment. 4. I have done homework already. 5. wewill have breakfast at 6.00. 6. She did her homework for 2 hours. 7. They bought a lot of beer last night. 8. Mrs. Nga has met the minister. 9. Tung and Hai play volleyball in the afternoon 10. He drove his car to Vai market last week. 11. Her house has a yard. 12. Classes end at 11.30. 13. My wife speaks 4 languages. 14. She drinks a little water after lunch 15. My mother goes home late. 16. Mozart was born in 1756. 17. Mozart died at the age of 35. 18. I was at home last night 19.The doctor will come here at 4 o'clock. 20. She speaks English fluently.