I know him for a long time.
I’ve known him for a long time.

Which is natural?

Vedi una traduzione

“I’ve known him for a long time,” is the most natural & proper usage in this example.

The difference is VERBAL TENSE (which expresses TIME reference)

“know” = present tense verbal form.

Example: “I know [about] him,” which doesn’t reference HOW LONG you’ve known him [or anything about him].

“known” = past tense form of “know” - which is the proper usage when speaking about someone with whom you share history, or have previous knowledge of.

Example: “I’ve known [about] him,” indicates much more about the LENGTH of TIME you may have known.

Keep up the great work, I hope this helps :)