From the top...Originally Posted by makaveli
We use the past perfect tense when we are talking about two actions that occured in the past when one happened before the other, for example:
I bought a ticket.
The film finished.
The film had already finished when I bought my ticket.
We use had to show which action/activity happen first.
There are some phrasal verbs that include the verb to have, e.g. "to have enough". When we form the past perfect tense we end up with "He had had enough". (Present perfect is: He's had enough)
He had had enough of her after she asked him to be quiet for the hundredth time.