Colorful Ideas

Used to express the first activity that was in progress when the second activity happened at the past.

i.e. I was doing my homework when my little sister cried last night.

      My friend and I were playing football on the court when the day started to rain 

For the negative response, we use WASN’T / WEREN’T

i.e. The teacher wasn’t explaining the topic when the bell rang.

       You weren’t studying when the power off.