A
She was studied English when the teacher entered the class.
She was studying English when the teacher entered the class.
While I was walking to the park, I see my old friend.
While I was walking to the park, I saw my old friend.
They was playing video games, while their mom was cooking dinner.
They were playing video games, while their mom was cooking dinner.
They watched TV when the lights go out.
They were watching TV when the lights went out.
The dog bark while the children was sleep.
The dog barked while the children were sleeping.
I was read a book when my phone ringed.
I was reading a book when my phone rang.
When Anna called I cooked dinner and was watch TV.
When Anna called, I was cooking dinner and watching TV.
While we was waiting we do homework
While we were waiting, we did homework
While I walked to school, it start rain.
While I was walking to school, it started to rain.