The past perfect tense of "know" is "had known." It is formed by using the past tense of the auxiliary verb "have" (had) followed by the past participle of the main verb (known).
The past tense of "exist" is "existed." The past perfect tense is "had existed."
The past simple tense is knew. e.g. "I knew the answer but I forgot. "The perfect past tense is had known. e.g. "I had known once, but I don't know now."
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 of "know" is "had known." It is formed by using the past tense of the auxiliary verb "have" (had) followed by the past participle of the main verb (known).
The past tense of "exist" is "existed." The past perfect tense is "had existed."
Known is the past participle of know. The present perfect tense of know is have/has known.
The past simple tense is knew. e.g. "I knew the answer but I forgot. "The perfect past tense is had known. e.g. "I had known once, but I don't know now."
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 is had set.
The past perfect tense of hope is had hoped.
The past perfect tense of "submit" is "had submitted."
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."