Present perfect tense

It's possible.

When I say "I have visited Japan", it might happen in the recent past or very long ago. Correct?

Those 4 words on their own would not be a natural statement. If it is in a reply to a question you would say "Yes, I have visited Japan." And then you might even add the time period. "Yes, I have visited Japan, about 10 years ago." But not 'last year', in which case you would say "Yes, I did visit Japan last year."

chipwThose 4 words on their own would not be a natural statement.

They could be, in the right context. They do not have to be in reply to a question.

chipw I have visited Japan, about 10 years ago.

I would simply say "I visited Japan about 10 years ago."

i agree, I too would simply say "I visited..." without 'have' but since the original post was in regards to using 'have' I gave him an answer that would use that word and still make sense.

Matthew Wai Assuming that I visited Japan decades ago, is it correct to say "I have visited Japan"?

Yes. That's correct. The correct use of the present perfect does not depend on how long ago the event occurred. In practice, most uses of the present perfect are probably in reference to events which occurred fairly recently, but that doesn't mean you can't a