Past Perfect

 The past perfect refers to a time earlier than before now. It is used to make it clear that one event happened before another in the past. It does not matter which event is mentioned first - the tense makes it clear which one happened first. 

Forming the past perfect

The Past Perfect tense in English is composed of two parts: the past tense of the verb to have (had) + the past participle of the main verb.

Subject	+had	+past participle
Affirmative
She	had	given
Negative
She	hadn't	asked.
Interrogative
Had	they	arrived?
Interrogative Negative
Hadn't	you	finished?