There is one phrase that kids in my part of the world inevitably seem to say—usually sometime around 6 or 7:
“You’re not the boss of me!”
The first time one of my children said it to me, I was a bit taken aback. At that point, most of his verbal style had come from his parents, and we had certainly never said such a thing. In fact, we had never heard any adult say that phrase or anything in that actual grammatical construction.
Think about it: In English, we hardly ever use the possessive form “noun of me”—we use “my noun.” So the natural way of saying “you’re not the boss of me” in English would be, “you’re not my boss.”
If one of my children had said that to me, I wouldn’t have been startled at all. In fact, they may have heard me say such a thing to them!
But “you’re not the boss of me”—that exact set of words—seems to be ubiquitous amongst American children. At some point, each child says that to a parent, to the point that parents can make each other laugh by quoting it at each other. If a parent says, “You’re not the boss of me!” we know they are imitating a kid.
So this means that kids have their own grammatical construction that, I’m guessing, gets passed from kid to kid, never being used by an adult in their hearing. (Except, perhaps, when they overheard their parents mocking them, which we hope never happens because we hope that our children don’t actually know how funny we find them, right?)
Perhaps “you’re not the boss of me” is kid-specific speech: like knock-knock jokes and fart jokes, meaningful only during some specific developmental period.
OK, maybe not the fart jokes.
http://itre.cis.upenn.edu/~myl/languagelog/archives/005037.html has a good explanation of some of the origins of this phrase. Kids are probably getting if from ‘the song by They Might Be Giants, “Boss of Me,” used as the theme song for the FOX TV show “Malcolm in the Middle” from 2000 to 2006. “You’re not the boss of me now, and you’re not so big,” goes the chorus’.
“Though the phrase “you’re not the boss of me” may owe some of its current popularity to the TMBG song, this bit of rebellious kid-speak has been kicking around since the late 19th century” — that’s what I figured. My kids definitely didn’t hear it in a song! I think it’s an integral part of modern kid culture, and the songs just reflect that.