`1`. Nam told me that his best friend would take him to the post office.

- Cấu trúc câu trần thuật:

+ S1 + told + O + (that) + S2 + V lùi thì

`2`. He stopped smoking 3 years ago.

- S + V2/ed + thời gian + ago = S + have/has + not + Vpp + for + khoảng thời gian

- stop + Ving: dừng hẳn việc đang làm

`3`. Some books have been bought by my father.

- Bị động hiện tại hoàn thành: S + have/has + been + Vpp

`4`. Although he was tired, he tried to finish his work.

- Although + S + V = In spite of + N/Ving: mặc dù

`5`. If I knew his adress, I could write to him.

- If 2: If + S1 + V2/ed, S2 + would/could + Vinf

1. Nam told me that his best friend would take I to the post office

            ⇒ Cấu trúc câu trực tiếp ⇒ gián tiếp dạng tường thuật :

                   S + said/ told + (that)+ S + V (lùi thì)

2. He stopped smoking three years ago ( chuyển câu từ thì HTHT ⇒ QKĐ)

3. Some books have been bought by my father ( câu bị động thì HTHT)

                ⇒ S + have/has + been + Vpp + by O

4. Although he was tied, he tried to finish his work ( cấu trúc although)

                ⇒  Although + S + V, S + V

5. If I knew his address, I could write to him ( cấu trúc câu ĐK loại 2)

                ⇒ If + S + Vqk, S + would/ could + Vinf