2. It’s used to express an action that lasted for a period of time and
interrupted by another action in the past.
Examples :
The teacher was giving us a lesson , when a little
swallow flied into the room.
While we were having supper , all lights went out .
The house was burning , when I entered it.
While / as / when / just as
3. Examples : As he was making his speech , the minster felt faint .
While the goal keeper was running , a bottle struck him
on the shoulder .
was
were + v – ing
while
As + Past continuous + Past simple
4. Example :
I was swimming when some one stole my clothes.
When the telephone rang , we were having breakfast .
When we were having breakfast , the telephone rang .
When Past simple + Past simple
past perfect + past simple
Past simple + past continuous
present simple + future simple
present perfect + future perfect