Yes, we/you/they were No, we/you/they weren't Специальные вопросы :
What / Where / How / What time….. + was/were + Ving…..?
What were you doing at that moment? Who were they waiting for?
Where were the guys walking? Where was Ted shoveling snow?
Why was Mr. Emerson climbing the stairs so quickly? Отрицательно-вопросительные предложения :
Why wasn’t she leaving for school? Wasn’t he learning English?
Were you not writing when the instructor admonished you?
Weren’t they talking to each other?
USE
Используется для действий в прошлом, которые продолжались какое то время но насколько оно было ограничено(когда действие началось и когда закончилось) не известно и неважно:
A wood fire was burning on the hearth? And a cat was sleeping in front of it. A girl was playing the piano and singing softly to herself. Suddenly there was a knock on the door.
The documents were lying turning clockwise.
Last year this time I was attending school.
Joe was starving when the other arrived.
Tom’s mother was cooking in the kitchen..
Who was hiding from the police?
We were getting ready to do a pantomime.
Когда в предложении указаны два действия одно из которых длительное другое короткое мы используем для длительного (past cont) а для короткого (past simple) действия объединяются при помощи слов when и while/as