Me: Thalia has a tooth. That's why she is drooling. In England we call it dribbling.
S: Why do you speak English even though you come from England?
Me: You mean why do I speak American English?
S: Yes.
Me: Because then people can understand me.
S: But how did you learn to speak a whole other language?...
(Yes. It is pretty impressive. Thank you for noticing.)
