PAST PERFECT

125. When you desire to express an action complete at some definite past time, you do not say:

We finished when they came, but, We had finished when they came.
Not, They went when we arrived, but, They had gone when we arrived.
Not, I worked six months when he began, but, I had worked six months when he began.

Can you see a difference in the meaning expressed in these sentences: I worked six months when he began; and I had worked six months when he began? This last sentence describes an action completed or perfected before some definite past time.

126. Past perfect time denotes an action perfected or completed at some definite past time. It is formed by using had and the past participle of the verb.

Remember always, with irregular verbs, to use the past participle. Never use the past time form with had.

Past Perfect Time
Singular	Plural
1st. I had seen.	We had seen.
2d. You had seen.	You had seen.
3d. He had seen.	They had seen.