过去进行时用法知识点

　　一. 表示过去某个时刻或某一时段正在进行的事或动作。

　　二. 谓语部分构成

　　was/ were+doing

　　三. 句式

　　肯定句：I was watching TV at that time.

　　否定句：I was not (wasn’t) watching TV at that time.

　　一般疑问句： Were you watching TV at that time?

　　特殊疑问句： What were you doing at that time?

　　四. 常用时间状语

　　then, at this/that time yesterday, at 5 o’clock yesterday, the whole morning, from5 to 6 last night.

　　五. 过去进行时与when, while, as引导的过去时间状语从句连用。

　　When I came back, my son was reading a book.

　　While we were talking, Lily was doing her homework.

　　六. 区分when 与while的用法。

　　when后即可以加时间点，又可以加时间段，while 只能加时间段。

　　when引导的句子即可以是延续性动词，也可以是短暂动词，while 后只能加延续性动词。

　　when 引导的句子即可以是一般时态，也可以是进行时态，while后通常加进行时态。

　　主从句都是延续性动词，都用过去进行时的时候，多用while 引导状语从句。即“…be doing sth. while …be doing sth.”

　　Lily was singing while Lucy was dancing.

　　反而时间状语从句。

　　结构为“be doing sth. when …”译为“正在做某事时突然…”,此句型不再强调主句，反而强调了时间状语从句所表达的意思，因而叫做反而时间状语从句。

　　I was taking a walk in the park when it began to rain.(我正在散步的时候突然下雨了。)

　　while 还可表示“然而”，起转折作用。

　　I like pop music while my brother likes folk music.