What is the difference between Had known and have known?

Answer 1

Excellent question!

I'll give some examples of their usage first; that will make it easier to explain.

I have known the answers to the first half of the quiz since the first time the teacher explained the material. I had known the answers to the second half of the quiz until last week, but now I cannot recall them.

Both refer to actions in the past, but 'have' implies a continuation until the present, while 'had' indicates that the action stopped at some point in the past.

I hope that makes sense. I feel that there is probably a better way of explaining it. I know exactly how to use the two tenses, but I'm having a hard time putting it into words. Hopefully someone else can improve on this. Meanwhile, here's another example:

I have been driving a Chrysler since 2008. I had been driving a Ford until 2008.

I hope this helps.

-HW

I was looking for something else today when I came across the answer to your question. Have known is the present perfect tense of the verb to know and is used when the knowing (1) happened at an indefinite time in the past or (2) began in the past and continues in the present. Had known is the past perfect tense of the verb and is used when the knowing happened in the past before some other action or situation. There is also a future perfect tense, will have known, which is used when the action will happen in the future before some other action or situation.