The past perfect is formed with - had + past participle. It is the same for all subjects.
The past participle of view is viewed so past perfect is - had viewed.
I had viewed the goods before the auction.
They had viewed the goods before the auction.
The bidders had viewed the goods before the auction.
Existed is the past tense. The past perfect tense is had existed.
The past perfect tense of hope is had hoped.
The past tense is bled, and the past perfect tense is had bled.
The past tense of sit is sat; the past perfect tense is had sat.
present tense past tense future tense present perfect tense past perfect tense future perfect tense present progressive tense past progressive tense future progressive tense present perfect progressive tense past perfect progressive tense future perfect progressive tense
The past perfect tense of 'get' is 'had gotten'
Perfected is the past tense of perfect.
"Had been" is the past perfect tense of be.
The past perfect tense of do is had done.
The past perfect tense of borrow is "had borrowed."
The past perfect tense of "think" is "had thought."
The past tense of paint is painted. Had painted is the past perfect tense.