derive初中英语过去进行时(when-while用法)

2021年1月10日发(作者：霍希贤)
Summary 3
Past Continuous Tense 过去进行时总结
I. Definition 时态含义
表示过去某一时刻或过去一段时间内正在进行的动作。

II. Time words 时间标志词
1. then, at that time, this time yesterday, at 6 o’clock yesterday ...
2. when/ while/ (just) as引导的时间状语从句

III. Structure 动词结构
was/ were + doing

When/ while/ (just) as 引导的时间状语从句在过去进行时态中的用法区别

1. when 既可以和短暂性动词连用，也可以和连续性动词连用，
句中一般翻译为“当......时候”/“就在那时”。
a. Someone knocked at the door when I was having breakfast.
b. I was taking a bath when the telephone rang.
2. while 只可以和连续性动词连用
句中一般翻译成“当......时候”（=when）/ “然而”（强调前后两个动作同时进行）
a. He cut himself while he was shaving.
b. My wife was cooking the dinner while I was working in the garden.
3. (just) as更强调“随着”，所引导的从句动作一般与主句动作伴随着发生。
a. Just as I was opening the front door, the telephone rang.
b. The children were singing as they went home.