THE PAST PERFECT TENSE
A. USE

The past perfect tense is often used in English when we are relating two events which happened in the past. It helps to show which event heppened first.
Past Perfect, geçmişte gerçekleşen iki olaydan birinin öncekine kıyasla daha önce gerçekleştiğini ifade etmek için kullanılır.

I went to see the movie. We had discussed it in class. (After we disscussed the movie in the class, I went to see the movie.)
I wanted to live in a foreign country, so I applied for a job in Japan. Judy had lived in Japan, so I called her to find out more about the culture and lifestyle there. (Judy didn' live in Japan any longer -- she returned from there before I applied for the job.)

B. STRUCTURE

Positive Structure:

I
You
He
She had worked.
It
We
They

Note: Use past participle of irregular verbs in both positive, negative structures and questions.

Negative Structure:

I
You
He hadn't
She had not worked.
It
We
They

Question structure:

I
You
Had He
Hadn't She worked?
It
We
They