Stative verbs in Present Perfect Tense
Incorrect : I know him for a long time. Or I have been knowing him for a long time.
Correct: I have known him for a long time.
Note: When we talk of an action which began in the past but continues into the present, we usually use the present perfect continuous tense. But in case of a stative verb, we must use the present perfect tense. See another example below:
Incorrect : I am here for two years. Or I have been being here for two years.
Correct : I have been here for two years.