过去进行时

1.概念:表示过去某段时间或某一时刻正在发生或进行的行为或动作。

2.时间状语:at this time yesterday, at that time或以when引导的谓语动词是一般过去时的时间状语等。

3.基本结构 主语+was/were +doing +其他

4.否定形式:主语+was/were + not +doing+其他

5.一般疑问句:把was或were放于句首。(第一个字母大写)

6.例句:At that time she was working in a PLA unit.

           When he came in, I was reading a newspaper.