过去进行时主要用于:
表示过去某个时刻或阶段正在进行的动作。
e.g. At that time she was working in a PLA unit.
那时她在解放军某部工作。
What were you doing this time yesterday?
与这个时态连用的时间状语常用:
at nine o`clock, this time last night, these days, at that time 等。
用 when 引导的时间状语从句表示主句的动作正在进行的时间。
e.g. When he came in, I was reading a newspaper.
注:
1 、 while 引导时间状语从句叙述过去的动作时,从句常用过去进行时。
e.g. I read a magazine while I was waiting for the bus.
2 、 when 用作并列连词,意为“这时”,连接两分句时,第一句多用过去进行时。
e.g. I was reading a newspaper when he came in.
一般过去时与过去进行时的区别:
一般过去时:强调过去某一时间开始或完成的动作。
过去进行时:强调过去某一时间正在进行的动作。
试区别下面两句: We were building a reservoir last winter.
去年冬天我们在修建一座水库。(可能尚未建成) We built a reservoir last winter.
去年冬天我们修建了一座水库。(已经建成)