Here are examples of sentences in the past perfect tense:
1. Positive Sentences
I had finished my homework before the teacher arrived.
She had already left when I called her.
They had visited the museum before it closed.
We had eaten dinner by the time they arrived.
He had completed the project before the deadline.
2. Negative Sentences
I had not (hadn’t) seen that movie before yesterday.
She had not (hadn’t) prepared for the test, so she was nervous.
They had not (hadn’t) met each other before the party.
We had not (hadn’t) heard the news until it was announced.
He had not (hadn’t) cleaned his room before his parents came home.
3. Questions
Had you finished your homework before the class started?
Had she arrived before the meeting began?
Had they already eaten by the time we reached the restaurant?
Had he ever traveled abroad before last year?
Had we prepared enough for the presentation?
4. Uses
Action completed before another past action: I had left the house before it started raining.
Experiences up to a point in the past: She had never been to New York before last summer.
Cause and effect in the past: He was tired because he had worked all day.