I'm going through some of this now with my son.... or I guess with my wife. I couldn't care less what words my son uses as he learns to express himself. My wife, on the other hand, keeps getting after me if I swear around him. Right now it's just a battle between the two of us. Eventually, it will be a battle between teachers as I tell him he can say whatever he wants because that's his right (except things like threats and verbal abuse, of course) and the teachers will try and control his speech to use only the approved vocabulary for no other reason than, "It's not a nice word." I don't really give a fuck and I'll certainly be on my son's side for that one.