If I had known you would ask this question, I would have studied English grammar more. In the previous sentences, "had known" is in the past perfect tense.
Past perfect is used to show one thing in the past happened before another thing in the past. This other thing in the past is usually expressed by past simple. eg
The train had left when I arrived at the station.
Had left is past perfect and this event happened before arrived which is past simple.
So you would use past perfect when telling a story about things in the past. eg
I felt really tired when I took the train to work yesterday because Sophie and I had been to a party the night before. We hadn't gone to bed until 3:00am. I had been on the train 5 minutes when I realised that I had left my wallet at home. I phoned Sophie but she had already left for work.
The past perfect tense of hope is had hoped.
"Had been" is the past perfect tense of be.
Depending on how you use the words some are already in the past tense. Got is the past tense of get. Present: I will get a dog. Past: I got a dog. With is a general term. It doesn't change in the past tense. Had is the past tense of has and had. Depending on which style of past you are using [progressive, perfect, progressive perfect, simple] will dictate how you use the word.
The past perfect tense is had broken.
The past perfect tense is had met.
Had turned is the past perfect construction. Use had + past participle to create the past perfect tense.
Yes, the past perfect tense of time is had timed.
The past tense of "exist" is "existed." The past perfect tense is "had existed."
The past tense of sit is sat. The past perfect tense of sit is had sat.
The past tense of "bleed" is "bled." The past perfect tense of "bleed" is "had bled."
The past perfect tense is had set.
The past perfect tense is had rung.
The past perfect tense is had bathed.
The past perfect tense of "confront" is "had confronted."
The past perfect tense of "learn" is "had learned."
The past perfect tense is had burned.
The past perfect tense of "submit" is "had submitted."