Beispiel:

I had been singing
You had been singing
He/she/it had been singing
We had been singing
You had been singing (Plural)
They had been singing

Wann wird das Past Perfect Continuous benutzt?

Das Past Perfect Continuous beschreibt einen länger dauernden Vorgang in der Vergangenheit, welcher vor einer anderen Handlung in der Vergangenheit stattfindet.

Beispiel:

Jenna had been waiting for two hours when Ben arrived.
We had been driving around for a day when we finally reached Las Vegas.

Bei Fragesätzen werden die Positionen von Subjekt und erstem Hilfsverb ausgetauscht.

Beispiel:

Had you been drinking alcohol?
Had they been waiting for us?

Bei Verneinungen wird das Wort “not” nach dem ersten Hilfverb eingesetzt.

Beispiel:

I had not been playing tennis.
She had not been looking after the children.