What Had Been Happening Before Something Occurred
Past Perfect Continuous
The past perfect continuous expresses the duration of an activity up to another point in time in the past. The use of the past perfect continuous stresses that a certain activity had been going on before something important happened.
Example:
How long had you been interviewing for the new personnel positions before the company's bankruptcy became public?
We hadn't been assessing the data for long when they demanded a firm percentile.
We'd been working on the peace-building process for five months when the ambassador rejected the plan's premise.
Positive Form:
Subject + had + been + 'ing' form of verb + (object(s)) + time expression
We'd been working on the peace-building process for five months when the ambassador rejected the plan's premise.
Negative Form:
Subject + had + not + been + 'ing' form of verb + (object(s)) + time expression
They hadn't been discussing the new technology for more than twenty minutes before the subject of its adaptive capacity was raised.
Question Form:
(Question Word) + had + subject + been + 'ing' form of verb?
How long had you been interviewing for the new personnel positions before the company's bankruptcy became public?
Past Perfect Contrasted with Past Perfect Continuous
The past perfect expresses something that finishes before another activity in the past. The past perfect continuous, on the other hand, expresses the duration of an activity at the moment something important happened in the past.
Past Perfect Examples:
I had already sought outside aid before the internal structure collapsed.
Had we coordinated this event with the other activist events on the schedule before we rented the room?
Past Perfect Continuous Examples:
How long had you been working on forming an advocacy alliance before the other nonprofit backed out?
We'd been working on the peace-building process for five months when the ambassador rejected the plan's premise.