Əvvəlcə misallara baxaq:

Yesterday morning I got up and looked out of the window. The sun was shining but the ground was very wet. It had been raining.
It was not raining when I looked out of the window; the sun was shining. But it had been raining before. That's why the ground was wet.

Keçmiş bitmiş davamedici zaman had been fel ing formasında düzəlir:

When the boys came into the house, their clothes were dirty, their hair was untidy and one of them had a black eye. They'd been fighting.
I was very tired when I arrived home. I'd been working hard all day.

Keçmiş bitmiş davamedici zamandan keçmişdə baş vermiş bir hadisədən daha əvvəl baş vermiş və davam edən başqa bir hadisəni ifadə etmək üçün istifadə edilir:

Our game of tennis was interrupted. We'd been playing for about half an hour when it started to rain very heavily.
Ken gave up smoking two years ago. He'd been smoking for 30 years.

Keçmiş bitmiş davamedici zaman İndiki bitmiş davamedici zamanın keçmiş formasıdır:

I hope the bus comes soon. I've been waiting for 20 minutes. (before now) -- At last the bus came. I'd been waiting for 20 minutes. (before the bus came)

He's out of breath. He has been running. -- He was out of breath. He had been running.

Keçmiş bitmiş davamedici zamanı keçmiş davamedici zamanla müqayisə edək:

It wasn't raining when we went out. The sun was shining. But it had been raining, so the ground was wet.
Ann was sitting in an armchair watching television. She was tired because she'd been working very hard.

Bəzi fellər var ki, davamedici zamanda işlənmir (know, want və s.):

We were good friends. We had known each other for years, ('had been knowing' -- yox)