It depends on the gender of the person you want to say that. If it is a girl it would be: أنا احبك (pronunciation: ana uhibbuki) If it a boy it would be: أنا احبك (pronunciation: ana uhibbuka) The wirtten form is the same in both cases, the only thing that changes is the pronunciation.

In Egyptian Slang it's " بحبك " to a Male " Bahebak " to a Female " Bahebek " and the letter " H " in both words should be pronounced like the letter " ح " in the Arabic language ! Cheers ;)