1. After David had gone, we arrived.

`=>` After + hiện tại hoàn thành, quá khứ đơn = quá khứ hoàn thành + before + quá khứ đơn

2. Before we took a look round the shop, we had had lunch.

`=>` Before + quá khứ đơn, quá khứ hoàn thành

3. When we got out of the office, the light had gone out.

`=>` Hành động diễn ra trước chia quá khứ hoàn thành, hành động diễn ra sau chia quá khứ đơn

4. By the time we started our work, she had explained everything clearly.

=>` By the time + quá khứ đơn, quá khứ hoàn thành

5. After my father had watered all the plants in the garden, my mother came home.

`=>` After + hiện tại hoàn thành, quá khứ đơn 

`1.` After David had gone home, we arrived.

`=>` After + QKHT, QKĐ.

`2.` Before we took a look round the shop, we had lunch.

`=>` Before + QKĐ, QKHT.

`3.` When we got out of the police, the light had gone out.

`=>` When + QKĐ, QKHT.

`4.` By the time we started out work, she had explained everything.

`=>` By the time + QKĐ, QKHT.

`5.` After my father had watered all the plants in the garden, my mother came home.

`=>` After + QKHT, QKĐ

`#Study well`