初二下册英语unit 3知识点总结

概要：e back home yesterday evening. 昨天晚上妈妈回家的时候，我正在做家庭作业。二、语法详解过去进行时：过去进行时表示过去某一时刻或者某段时间正在进行或发生的动作，常和表过去的时间状语连用，如：I was doing my homework at this time yesterday.过去进行时的构成：肯定形式：主语+was/were+V-ing否定形式：主语+was not (wasn‘t)/were not (weren‘t)+V-ing疑问形式：Was/Were+主语+V-ing.基本用法：1.过去进行时表示过去某一段时间或某一时刻正在进行的动作。常与之连用的时间状语有，at that time/moment， this time yesterday at+点钟+yesterday ，when sb. did sth等时间状语从句，如：What were you doing at 7p.m. yesterday?I first met Mary three years ago.She was working at a radio shop at the time.上一页 [1] [2]

　　While Jim was mending his bike， Lin Tao came to see him. 正当吉姆修自行车时，林涛来看他。

　　(3) 另外，when和while的区别还在于：while引导的时间状语从句多用进行时态，而when引导的时间状语从句多用一般时态。

　　While they were talking ， the bell rang. 正在他们谈话的时候，上课铃响了。

　　I was doing my homework when my mother came back home yesterday evening. 昨天晚上妈妈回家的时候，我正在做家庭作业。

　　二、语法详解

　　过去进行时：过去进行时表示过去某一时刻或者某段时间正在进行或发生的动作，常和表过去的时间状语连用，如：

　　I was doing my homework at this time yesterday.

　　过去进行时的构成：

　　肯定形式：主语+was/were+V-ing

　　否定形式：主语+was not (wasn‘t)/were not (weren‘t)+V-ing

　　疑问形式：Was/Were+主语+V-ing.

　　基本用法：

　　1.过去进行时表示过去某一段时间或某一时刻正在进行的动作。常与之连用的时间状语有，at that time/moment， this time yesterday at+点钟+yesterday ，when sb. did sth等时间状语从句，如：

　　What were you doing at 7p.m. yesterday?

　　I first met Mary three years ago.

　　She was working at a radio shop at the time.

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