Past continuous: Subject + was/were + gerund
To understand the past continuous well, you need to understand the verb to be
We use the past continuous to talk about a past action that is in progress.
I was running as fast as I could when suddenly I fell on the floor.
I was not working at 11pm last night.
We use the past continuous to talk about non-important information in the past.
It was raining when you called me last night.
The music was playing really loudly.
We use the past continuous with words such as while/whilst/as.
While I was watching the movie, you were answering your emails.
As I was not working hard, my boss fired me.
We use the past continuous to talk about past actions in progress at a specific time.
At 5am I was still sleeping soundly in my bed.
I was not listening to music at 7am when you rang me, I was watching TV.
To form a question, we use AUX + SUBJECT + GERUND
Were you working last night when I called you?