A2
Past Continuous: Past Continuous Tense in English
Past Continuous shows an action in progress at a moment in the past, or the background for a shorter Past Simple action.
Form: was / were + verb + -ing.
I was reading at 8 p.m.They were waiting for the bus.She wasn't sleeping.Were you working?
Two tenses together
I was cooking when the phone rang.— cooking in progress; the phone — a short eventWhile we were walking, it started to rain.
Do not use continuous with stative verbs: I knew the answer, not I was knowing.