We have told our 3 year old not to say Butt, Darn it, Stupid, Duh!, and now Oh my gosh. I don't mind the darn it or oh my gosh, since we say those around him instead of the more risque words...but the funny things are when he points out a "dump truck" and tells us what it is...he pronounces the "tr" as "f" and forgets the "p" on the end of "dump"...also when talking about Thomas the train, he talks about how much he likes Percy--although he can't do "er" as anything but "uw"...you figure it out...