The Past Continuous (also called the Past Progressive) is used in several different ways:

• interrupted actions in the past
• parallel actions in the past

It is used to reference a continuous (long-term) action in the past:

They were kissing when we walked in.

He was working when we met him.

Usage

Interrupted Actions/Background

We use the past continuous to talk about an action taking place in the past which is interrupted by another action (this can be considered as a background action).

I was eating my lunch when somebody knocked at the door.

On a time scale, the first example would look like this:

1.00 pm: start eating lunch
1.10 pm: still eating lunch
1.11 pm: knock at door; stopped eating lunch

Eating is the action that had started, and was still in progress, when the second action – somebody knocking at the door – took place.

You’ll notice the second action is often described with the past simple‏‎, Because of the type of actions that the past continuous and the past simple‏‎ describe, these two verb forms are often used together.

{past continuous} + {past simple}

Joe was smoking a cigarette when the police broke down his door.

They were walking in the countryside when it began to rain.

Parallel (Background) Actions

We use the past continuous to talk about two or more continuous actions happening at the same time in the past. If you like, they provide a background to the story.

Everyone was cheering while the band was playing.

No one expected anything. The kids were playing upstairs and Harry was planting vegetables in the garden. Martha was in the kitchen making dinner and Uncle Joe was watching tv.

Temporary and Continuous

These are long term actions in the past which no longer occur:

I was working at home all last week.

The factory was turning out thousands of uniforms during the war.

Past Arrangements

For arrangements in the past:

They were leaving on the six o’clock train.

Of course he was nervous, he was flying to the moon the next morning.

Form

We make the past continuous by using the past tense of the verb to be (was/were) and the present participle (the -ing form) of the main verb:

{subject} + {was/were} + {present participle}

I was working when you called.

They were kissing when her father entered the room.

Note Stative Verbs‏‎ are not usually used in the continuous form.

See Also

Verb Tenses‏‎ & Forms in English Grammar

Busy People – past continuous‏‎ activity