"I have not seen you for a long time."

Translation: Я давно не бачив тебе.

[breadstick42]

"я тебе не бачив давно" чому це неправильно?

[KUVOLIGO]

В мене така само помилка!..

[piguy3]

Could this also be translated with a present tense verb?

[deactivated user]

It could work if you're writing a letter, talking on the phone or otherwise communicating with a person without seeing them. If you are talking with someone in person, you can only use the past tense.