The continuous perfect past tense points to a time between an event and before it.
The rule (active voice):
Positive Sentence Structure:
subject + had + been + [verb+ing] + obj/ect .Example: I had been working for one month.Before I got a raise
Negative Sentence Structure:
subject + had + been + [verb+ing] + obj/ect .Example: I hadn't been driving for one day until my car was fixed
Question Structure:
had + subject + been + [verb+ing] + obj/ect .Example: Had you been working for one the entire day?
Tag Question Structure:
had + not(if the sentence before it was positive) + ? .Example: I had been working for one month before I got a raise. hadn't I?
The rule (passive voice):
Positive Sentence Structure:
subject + had + been + being + verb (past particable form) + obj/ect .Example: My exam had been being written for a day before yesterday.
Negative Sentence Structure:
subject + had + been + being + verb (past particable form) + obj/ect .Example: My exam hadn't been being written for a day before yesterday.
Question Structure:
had + subject + been + being + verb (past particable form) + obj/ect .Example: Had my exam been being written before two days?
Tag Question Structure:
had + not(if the sentence before it was positive) + ? .Example: My exam had been being written for a day before yesterday. Hasn't it?
Adverbs:
before + time.
an event in the past