1. have seen

- HTHT since QKĐ
2. had already left

- QKHT when QKĐ

3. had finished

- After QKHT, QKĐ

4. had worked - worked

- QKHT before QKĐ

5. had just started - rang

- QKHT when QKĐ

6. had listened

- before QKĐ, QKHT

7. went - had done

- QKĐ after QKHT

8. had shouted

- QKHT: S had VPII

9. had finished

- QKHT by the time QKĐ

10. arrived - had finished

- by the time QKĐ, QKHT

`1.` had seen

QKHT + before + QKĐ

`2.` had already left 

QKHT + when + QKĐ

`3.` had finished 

After + QKHT + QKĐ

`4.` had worked, worked

QKHT + before + QKĐ

`5.` had just started, rang

QKHT + when + QKĐ

`6.` had listened

Before + QKĐ + QKHT

`7.` went, had done

QKĐ + after + QKHT

`8.` had shouted

QKĐ + because + QKHT

`9.` had finished

QKHT + by the time + QKĐ

`10.` arrived, had finished

By the time + QKĐ + QKHT

*Cấu trúc thì quá khứ đơn:

(+) S + V_ed/ V2

(- ) S + didn't+ V_inf

(? ) Did + S + V_inf?

*Cấu trúc thì quá khứ hoàn thành:

(+) S + had + V_ed/ V3

(- ) S + hadn't + V_ed/ V3

(? ) Had + S + V_ed/ V3?