1.过去进行时的各种句式:
肯定句:主语+ was / were+动词-ing形式。如:I was reading at this time yesterday.
昨天这个时候我正在看书。
否定句:主语+ was / wrerumernot+动词-ing形式。如:
l wasn't reading at this time yesterday.昨天这个时候我没在看书。

疑问句:
(1)一般疑问句: was / were+主语+动词-ing形式。肯定回答: Yes,主语+ was / were.否定回答:No,主语+ wasn't / weren't.如:-Were you reading at this time yesterday?—昨天这个时候你在看书吗?
- Yes, I was./ No, I wasn't.—是的,我在看。/不,我没在看。

(⑵特殊疑问句:疑问词+ was / were +主语+动词-ing形式。如:
What were you doing at this time yesterday?昨天这个时候你在做什么?
What was he researching all day lastSunday?
上周日他一整天都在研究什么?