PAST Perfect

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.

 

 

We form past perfect with:

A subject:  I, you, he, she, we, etc.

The auxiliary had

The past participle form of the verb.

So, the structure to make an affirmative sentence is:

Subject + aux had + verb in past participle + complement

 

Example

Sub           Aux.         Past participle

He     had     played     football.

They had had two dogs.

You had done your homework.

 

 

Here there is more information and exercises for you to practice.

http://www.englishbaby.com/lessons/grammar/past_perfect_tense

http://www.englishclub.com/grammar/verb-tenses_past-perfect_s.htm

http://www.ego4u.com/en/cram-up/grammar/past-perfect-simple/exercises?03

http://www.perfect-english-grammar.com/past-perfect-exercise-1.html