The past perfect tense is had met.
The past perfect tense of hope is had hoped.
"Had been" is the past perfect tense of be.
No, meet is present tense. The past tense is met.
The past perfect tense is had borne.
The past perfect tense is had broken.
Had not met is past perfect. Not is an adverb and does not change from one tense to another.
The past tense of "exist" is "existed." The past perfect tense is "had existed."
The past tense of "bleed" is "bled." The past perfect tense of "bleed" is "had bled."
The past tense of sit is sat. The past perfect tense of sit is had sat.
The past perfect tense of hope is had hoped.
The past perfect tense of "submit" is "had submitted."
The past perfect tense is had set.
The past perfect tense is had rung.
The past perfect tense of "confront" is "had confronted."
The past perfect tense is had burned.
The past perfect tense of "learn" is "had learned."
The past perfect tense is had bathed.