Verbs - Present Perfect Continuous

We use the present perfect continuous for actions that had been happening for a period of time before the past time you are thinking about. e.g. I was exhausted when I arrived home. I'd been working hard the whole day.

POSITIVE SENTENCES (‘d / had been + ing)
I/You/He/She/It/We/They had been playing for two hours before realising it was time to go home.

The students had been imitating the teacher during the lesson and that's why they were sent home.
His grandmother wasn't well and he had been helping her for some time.
The forest fire had been burning for a few hours before the fire brigade arrived.
Her mother had been calling her for quite a while before she finally responded.

NEGATIVE SENTENCES (had not (hadn’t) been + ing)
I/You/He/She/It/We/They hadn’t been watching TV when the doorbell rang.

The teenagers hadn't been hitch hiking when the police found them.
I told them not to make a noise but they hadn't been keeping quiet so I didn't take them to the park.
He hadn't been introducing the guests when he was called to make a speech.
We hadn't been holding on tightly and that's why we were injured in the accident.

QUESTIONS
Had I/you/he/she/it/we/they been waiting for Caroline's arrival?

Had the clubbers been hanging up their coats before entering the club?

Had Kate been climbing that tree when she fell and broke her arm?

Had the builders been building that house when the earthquake occurred?

Had they actually been carrying those heavy rucksacks across Canada?