English Grammar - Verbs - Past Perfect

FORM - Past Perfect
+ HAD + past participle
Examples:
I had arrived
USAGE:
We use the past perfect when we wish to stress that one action or situation in the past occurred before another action or situation in the past.
Examples:
We had never seen such a beautiful place before I went to Miami.
USE 2 Duration Before Something in the Past
We use the Past Perfect to show that something started in the past and continued up until another action in the past.Examples:I had had this house for ten years before it was in fireBy the time Jonh finished his studies, he had been in Paris for over five years.
Finally, the past perfect tense is also used in third conditional sentences.
If she had studied harder, she would have passed her exams.