英语 过去进行时的构成和分析

表示过去某时正在进行的状态或动作.
句式：主语+was/were+动词ing+其他.
种类:1.表示过去某一时间内（正在）进行的动作
如：I was doing my homeworks at 9 o'clock p.m. last Sunday.
2.表示一动作正在进行时,另一动作同时正在进行.
如：I was reading books while he was cleaning the floor.
3.表示一个动作正在进行时,另一个动作发生了
如：he played when I was studying.
4.表示过去将要发生的动作
She told us Mr.Lee was arriving here.
5.用于故事,以提供其时间背景
6.表示礼貌
肯定句：主语+was/were+doing+其它
否定句：主语+was/were+not+doing+其它
一般疑问句及答语：Was/Were+主语+doing+其它 答语：Yes,I was./No,I wasn't.
特殊疑问句：特殊疑问词+was/were+主语+doing+其它

结构
1. was/were+Ving
eg:My morther was cooking at 6:00p.m. yesterday.（直接表达）
2. 用while连接
eg:My mother was cooking while I was doing my homework.(可以持续动作时态一致)
3. when表示
eg:I was doing my homework when my mother came in.(间接表达了具体时间)