Past Perfect
Had known.
Present Perfect
Have/has known.
Future Perfect
Will have known.
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 term "had known" is the past perfect tense. Had is an auxiliary verb. Known is the past participle of the verb know.
This is the imperfect tense. (verb)= present tense (verb)ed= perfect tense was (verb)ing= imperfect tense Perfect and imperfect are both forms of the past tense.
The present perfect tense of "they have" is "they have had."
It is a tense of a verb.
The past perfect tense of the verb "contain" is "had contained."
The present perfect tense of the verb "study" is "have studied."
"have tried" is the present perfect tense.
The word "has" is not a future perfect verb. It is a present tense verb that functions as a helping verb for forming perfect tenses. In future perfect tense, "has" is combined with the auxiliary verb "will have" to show an action that will be completed at some point in the future.
Past simple --- knew.past continuous -- was/were + knowingpast perfect -- had + knownpast perfect continuous -- had + been + knowing
The perfect tense of the verb "save" is "has/have saved." For example, "I have saved enough money to buy a new car."
The present perfect tense of the verb "search" is "have searched" or "has searched."