The boy will probably be capable of developing relatively normally - granted he has a handicap of a few years. But the 'language expiration date', the point at which people stop being able to acquire language how they should as a child is puberty. He still has a ways to go and will be able to learn at the very least the basics of human communication. Granted, as children get older, their ability to learn new linguistic capabilities becomes less and less radical. A three year-old can learn something like two hundred words per day. He just won't have had all eight years, but still has three or four. I'm just glad they found him before it was too late; and thank god the mother wasn't crazy enough to beat him or anything.