IX. Change these sentences into positive, negative, yes-no or Wh_questions.
1. They cleaned the beach one week ago.
(-) They didn't clean the beach one week ago.
(?) Did they clean the beach one week ago?

Cấu trúc câu thì quá khứ đơn:

(+) S + V2/ed +…

(-) S + did not + V (nguyên mẫu)

(?) Did + S + V (nguyên thể)?
2. She has flew(flown) to DaNang many times.
(-) She hasn't flew(flown) to DaNang many times.
(?) Has she flew(flown) to DaNang many times?

Cấu trúc câu thì hiện tại hoàn thành:

(+) S + have/ has + VpII

(-) S + have/ has + not + VpII 

(?) Have/ Has + S + VpII +… ?
3. There are not many community services you can join in.
(+) There are many community services you can join in.
(?) Are there any community services you/i can join in?

=> Cấu trúc câu there is/ there are:

(+) There are + số lượng + danh từ đếm được số nhiều

(-) There + are + not + danh từ 

(?) Is/ Are + there + danh từ
4.  Have you finished your homework yet?
(+) I have finished my homework.
(-) I haven't finished my homework yet.

Cấu trúc câu thì hiện tại hoàn thành:

(+) S + have/ has + VpII

(-) S + have/ has + not + VpII 

(?) Have/ Has + S + VpII +… ?

5. He has collected clothes for streets kids for two years.
(-) He has not collected clothes for streets kids for two years.
(?) Has he collected clothes for streets kids for two years.

Cấu trúc câu thì hiện tại hoàn thành:

(+) S + have/ has + VpII

(-) S + have/ has + not + VpII 

(?) Have/ Has + S + VpII +… ?

6. Traditional volunteer activities include raising money for people in need.
(-) Traditional volunteer activities don't include raising money for people in need.
(?) Do traditional volunteer activities include raising money for people in need?

Cấu trúc câu thì hiện tại đơn:

(+) S + V/ V(s/es) + Object…

(-) S do/ does + not + V +…

(?) Do/ Does + S + V?

7. He didn’t wear enough warm clothes.
(+) He wore enough warm clothes.
(?) Did he wear enough warm clothes.

Cấu trúc câu thì quá khứ đơn:

(+) S + V2/ed +…

(-) S + did not + V (nguyên mẫu)

(?) Did + S + V (nguyên thể)?