过去进行时句型结构：
juxing
1.肯定句形式：主语+was/were+doing（现在分词）+其他。
Iwasdoingmylessonsthen.
那时，我在做功课。
Wewerecleaningthehouseatthistimeyesterday.
我们这个时候在打扫房子。
2.否定形式：主语+wasn't/weren't+doing（现在分词）+其他。
Iwasn'tdoingmylessonsthen.
那时，我没在做功课。
Weweren'tcleaningthehouseatthistimeyesterday.
我们这个时候没在打扫房子。
3.一般疑问句形式：Was/Were+主语+doing（现在分词）+其他?
肯定回答：Yes,主语+was/were.
否定回答：No,主语+wasn't/weren't.
—Wereyoudoingyourlessonsthen?
—Yes，Iwas./No,Iwasn't.
Weretheycleaningthehouseatthistimeyesterday?
—Yes,theywere./No,theyweren,t.
4.特殊疑问句形式：特殊疑问词+was/were开头的一般疑问句?
—Whatwashedoingatthistimeyesterday?
—Hewasreadingbooks.