I've learned a lot about kids in recent years. Having two of them will do that to you. I've learned that my kids will repeat anything you say. And they'll learn the context if you use the same phrase twice. I've also learned that they are conditioned fairly early on how to respond to certain phrases. That's why my 1 year old daughter will say "Yessir" from the next room if I ask my son "Do you understand me?" It also means that they try to use my phrases against me.
So, here's a good example of these things. Yesterday, I told my son that he could have a Coke if he was good at the grocery store. So on the way home from the grocery store, I informed him that he was very well-behaved and had earned the promised Coke. Then I told him that he could have it with dinner as soon as he finished his bath.
His response was, "Um, how 'bout NO?"
And I know where he got that from. It was me. I say that to him when he suggests something ridiculous ("Daddy, how 'bout we paint the wall red?") So I guess he was just trying out my phrase. And I wanted to make sure he knew that he couldn't use that with us. My wife didn't help, though. Being the responsible adult that she is, she crumbled into fits of laughter. I, on the other hand, turned my rearview mirror to an angle that faced my son. Then I raised my eyebrows and said in my most serious voice, "Excuse me?"
And my son knows what that means. If I say "Excuse me?" then he is supposed to rethink what he just said and rephrase it in a kind way or by adding "sir" to the end of it. So I witnessed his tiny little eyes widen in horror as he realized what he'd said. Then I could almost see him back-pedaling in his mind (or maybe looking for an emergency exit).
So he gathered his thoughts and said sheepishly, "I mean... how 'bout okay... sir?"
That's when I crumbled into fits of laughter. He's a good kid. He tries hard.