Past continuous: An action in progress at a past time

The past continuous describes an action or situation that was in progress at a particular time in the past. It is formed with was / were + the -ing form.

Examples

At nine o'clock, I was driving home.

The journey was in progress at a specific past time.
The children were sleeping when the storm began.

The longer action was already in progress when another event happened.
While Noor was cooking, I was setting the table.

Two actions were happening during the same past period.

Past continuous vs. past simple

Past simple

I read the report last night.

The report is presented as a complete past event.

Past continuous

I was reading the report when you called.

The reading was in progress when the call occurred.

Read presents a completed event. Was reading gives the background or an action in progress around another past event.

It can describe temporary background situations

The past continuous is not limited to actions interrupted by a short event. It can establish the temporary background to a story or describe a changing situation.

That summer, we were living near the coast.

The situation continued for a limited past period.
The wind was getting stronger.

The continuous form presents a gradual change in progress.