Past Simple and Past Continuous in Contrast

We use the past simple to talk about states, habits or single events at a definite time in the past.

We use the past continuous to talk about actions and temporary states that were in progress around a certain point in the past.

Compare these examples:

At 12 o’clock I was having lunch in the office.
The action was in progress, it was not completed at this time.

At 12:15 I finished lunch and went back to work.
We emphasize that these actions were completed at this time.

We wrote several reports last month.
The action was completed.

We were working on several projects last week.
We do not know if these actions were completed.

When I was young I lived in Canada.
This was a state that was true for a long time.

I was living in London for a couple of weeks.
This was just a temporary state.

We use the past simple to talk about several events in the past that were completed in a sequence.

I got up, had a shower, got dressed and went to the office.

When one action is more important than the other we use the past simple to focus on it. We use the past continuous to talk about background events.

I was working (background event) on my report when Ann phoned(main event).

I was sitting (background event) at my desk and looking (background event) for inspiration and suddenly I had (main event) a great idea!