Structure: subject + was/were + -ing form of the verb

She was reading.

They were playing.

I was standing.

The birds were singing

The girls were waiting for the bus.

The child was drawing a picture.

1. The past continuous tense is used to talk about an action going on at a point of time or over a period of time in the past.

I was resting the whole day.
They were playing the whole evening.

2. To describe an action that was in progress when another action took place.

They were sleeping when the thieves broke in.
The lights went out when I was reading.

The telephone rang while I was working in the garage.