Here's one: "Wait, what?"
Scout has picked this up like an airborne linguistic virus.
I'll be explaining something, often not to Scout but to her mother, and Scout will interrupt and say, "Wait, what?"
It sounds dumb, I tell her. It makes her sound like a dumb girl trying to keep up. No, it makes her sound like a smart girl trying to sound like a dumb girl trying to keep up.
It's not just a teenage thing. Rachel Maddow does it too. From her website: "VP-elect Mike Pence is in a legal fight over access to his emails. Wait ... what?"
Don't be that guy. Don't be that girl.