We use the Past Progressive to describe past situations or actions that were in progress at some time in the past:

• I was living abroad in 1987, so I missed the general election.

Often we don't know whether the action was completed or not:

• Philippa was working on her essay last night.

Adverbials beginning with all emphasize continuity:

• It was raining all night/all yesterday/all the afternoon.

In the same way, still can emphasize duration:

• Jim was talking to his girlfriend on the phone when I came in and was still talking to her when I went out an hour later.

The Past Progressive and the Simple Past are often used together in a sentence. The Past Progressive describes a situation or action in progress in the past, and the Simple Past describes a shorter action or event. The action or situation in progress is often introduced by conjunctions like when and as, just as, while:

• Just as I was leaving the house, the phone rang.

• Jane met Frank Sinatra when she was living in Hollywood.

Or the shorter action can be introduced by when:

• We were having supper when the phone rang.

We can often use the Simple Past to describe the action in progress, but the Progressive puts more emphasis on the duration of the action, as in the second of these two examples:

• While I fumbled for some money, my friend paid the fares.

• While I was fumbling for some money, my friend paid the fares.

We can emphasize the fact that two or more actions were in progress at the same time by using e.g. while or at the time (that):

While I was working in the garden, my wife was cooking dinner.

This use is similar to that of the Present Progressive:

When he worked here, Roger was always making mistakes.

This use is even more polite and tentative than the Simple Past:

I was wondering if you could give me a lift.