过去进行时用于描述在过去某个特定时间或时间段正在进行的动作。它通常与时间状语如“when”、“while”等连用，来强调动作的持续性。以下是一些过去进行时的例子：

While I was walking home, I saw a beautiful sunset.

I was reading a book last night when I suddenly heard a knock on the door.

At 8 o'clock last night, I was watching TV.

She was reading a book at that time.

We were playing football.

We were having supper when the phone rang.

This time yesterday Jack was not watching TV.

He was repairing his bike.

When/While we were having supper, the light went out.

While we were talking, the teacher came in.

While he was waiting for the bus, he was reading a newspaper.

He was cleaning his car while I was cooking.

Tom was getting up at six o’clock every day that week.

He fell asleep when he was reading.

We were expecting you yesterday.

He was playing while I was studying.

I was wondering if you could give me a lift.

We were hoping you would stay with us.

I was having a talk with Li Hua at that time.

I was watching TV at home last night.

It was raining when they left the station.

When I got to the top of the mountain, the sun was shining.

Mary was making a dress when she cut her finger.

As she was reading the newspaper, Granny was falling asleep.

这些例子展示了过去进行时在不同句子中的用法，强调了动作在过去某个时刻的持续性或同时性。