past perfect
The Past Perfect expresses the idea that something occurred before another action in the past. It can also show that something happened before a specific time in the past.
FORM
[had + past participle]
[had + past participle]
Examples:
You had studied English before you moved to New York.
Had you studied English before you moved to New York?
You had not studied English before you moved to New York.
You had studied English before you moved to New York.
Had you studied English before you moved to New York?
You had not studied English before you moved to New York.
