Forms: I had been working.
The past perfect progressive is used to talk about actions or situations which had continued up to the past moment that we are thinking about, or shortly before it.
When I found Jane, I could see that she had been crying.
Compare progressive and simple
progressive simple
more temporary actions and situations longer-lasting or permanent situations
emphasise the continuation of an activity emphasise the idea of completion
some verbs are not normally used in
progressive forms
