He was working - He wasn't working - Was he working?
the auxiliary verb for the past continuous is to be. To be is part of the form of the tense ( to be + verb+ ing)
You use the past continuous:
- for actions that were in progress at some point in the past
- for actions that were in progress but were interrupted by another event ( when/while)
- to emphasize that two actions were happening at the same time in the past
- with always/forever for repeated actions or behaviour
mind! the continuous cannot be used with static verbs ( describes a state instead of an action)
I knew he was quite wealthy
I was knowing he was quite wealthy