We use the past continuous to talk about past events which went on for a period of time. It is formed with the past tense of to be and the -ing form of the main verb.
At 11.00 am yesterday I was studying for my History exam
For the negative form we use the negative form of to be.
I wasn't having an argument with him. We were just chatting.
For the interrogative form we place the past of to be before the subject.
Were they playing football when you saw them?
We use it when we want to emphasize the continuing process of an activity. (If we just want to talk about the past event as a simple fact, we use the past simple.)
Were you waiting for me?
Sorry, were you sleeping?
We often use it to describe a background action" when something else happened.
I was walking in the street when I suddenly fell over.
Now, it's time to practise. Here are some exercises. Do them and check that you understand this tense.
Exercise 1.
In the negative form
Exercise 2.
Two games
Contrast past simple/past continuous.