I changed the radio station in the car:
S: Why did you change that song? I liked that song!
Me: I didn't like that song because the singer was swearing.
S: What does swearing mean?
Me: Swearing is saying bad words.
S: What bad words?
Me: Uhh, really bad words that would get you in trouble with your teacher if you said them at school. I don't want you to get in trouble.
S: Like what bad words? Tell me, please. Pleeeease!
Me: I'm not ready to teach you any swear words, honey. Maybe when you're a little older we'll talk about it.
S: But you said swear words! I heard you! You said bad words!
Me: I did? Like what!
S: You said, "I swear!" I heard you!
Me: I said that I swear? What word did you hear me say?
S: No, you said, "I swear!" Just like that. "I swear." I heard you say that! You shouldn't say that!...
At that point, I realized that I must have muttered "I swear!" under my breath about something annoying me. I can't remember what about, though...Nevertheless, Sophia's scandalized reaction struck me as hysterically funny, and I laughed uncontrollably for a bit. She laughed along unwittingly.
When I finally settled down, I gave her a basic primer on how words can be good, bad, or somewhere in between, depending on the word and the situation:
Me: Like the word "poop," for example.
S: Hahaha! "Poop!" Hahaha!...
OK. Bad words training is off to a crappy start...