THE PAST CONTINUOUS TENSE IS USED FOR:
1. Actions in progress in the past:
I was living abroad in 1993, so I missed the election.
2. Actions in progress which began before something else happened:
We were having supper when he came.
3. Parallel actions in the past:
I was reading while he was watching TV.
4. Frequently repeated actions in the past causing the speaker's annoyance:
When he worked here, Denis was always making mistakes.
5. Polite inquiries:
I was wondering if you could do me a favour.
6. Without a time expression to indicate gradual change in the past:
It was getting colder.
7. With a point in time for an action which began before that time and probably continued after it:
At 8 p.m. he was watching TV.
8. In narrative for descriptions:
One morning the sisters were sketching by the side of Willey Water, at the remote end of the lake. Ursula was watching the butterflies, of which there were dozens near the water...
9. As an alternative to the Simple Past to indicate a more casual, less deliberate action:
I was talking to her the other day...
Practical Grammar Year 1
Agnieszka Piasecka