过去进行时由was/were加现在分词构成。

例如：

What were you doing this time yesterday?昨天这个时候你在做什么?

During the summer of 1999 she was travelling inEurope.1999年夏天她在欧洲旅行。

He said he was leaving for home in a day or two.他说他一两天之内就动身回家了。

She was always thinking of others.她老是想到别人。(赞扬)

She was for ever complaining.她老是抱怨。(厌烦)

I was reading the newspaper when the door bell rang.我正在看报，突然门铃响了。

Jim burn this hand when he was cooking the dinner.吉姆做饭时把手烫了。

I met Diana while I was shopping this morning.我今早买东西时碰到了戴安娜。

I was doing my homework while he was listening to music.我在做作业而他在听音乐。