1. He said He was going to work in HCM the following July

=> Đổi I-> He, lùi thì và next July đổi thành the following July

2. He worked for a big company

-> thì hiện tại lùi thì thành quá khứ đơn

3. He was their marketing manager

-> lùi thì

4. The company had opened an office in HCM city

-> HTHT lùi thì QKHT

5. It had been very successful

-> lùi thì tương tự câu 4

6. I had been chosen to run an office in District 5

7. He asked How long I had been learning English.

8. He didn't have much time to enjoy himself.

9. He hoped I would come and visit him in HCM city

10. He hoped I would be successful in HCM city

=>
1. Thuan said that he was going to work in Ho Chi Minh City the following July.
2. Thuan said that he worked for a big company.
3. Thuan said that he was their marketing manager.
4. Thuan said that the company had opened an office in Ho Chi Minh City.
5. Thuan said that it had been very successful.
6. Thuan said that he had been chosen to run an office in District 5.
7. Thuan asked me how long I had been learning English.
8. Thuan said that he didn't have much time to enjoy himself.
9. (Thuan said that) he hoped I would come and visit him in Ho Chi Minh City.
10. (Thuan said that) he hoped he would be successful in Ho Chi Minh City.
Câu tường thuật dạng Wh questions : asked sb + từ để hỏi + S V(lùi thì)
Câu tường thuật -> lùi thì
HTĐ -> QKĐ
HTHT -> QKHT
Will -> Would
Is/Am/Are going to V -> Was/were going to V