Auxiliary verb(s) for Past Continuous
was/were
It gives importance to the completion of the activity
Past Perfect
They all were wear coats because of the cold
They all were wearing coats because of the cold
Was/were + ing
Past Continuous
Auxiliary verb(s) for Paste Perfect Continuous
had, been
To describe finished actions in the past
Past Simple
I went to Ireland last year
I went to Ireland last year
Had + Past Participle
Past Perfect
Auxiliary verb(s) for Past Simple
did/didn´t
It gives importance to the duration of the activity
Past Perfect Continuous
I was tired because I had been studing all night
I was tired because I had been studing all night
ed/did-din´t
Past Simple
Auxiliary verb(s) for Past Perfect
had
To describe scenes in a story
Past Continuous
When the interview had finish, I left
When the interview had finished, I left
Had + been + ing
Past Perfect Continuous