Opposites

We were playing a game of opposites yesterday. It's the first time I've really introduced the concept and Maya surprised me in how quickly she picked up on it. She was able to correctly identify the opposites of things like day, in, up, happy, on etc. etc. then S asked her "What's the opposite of smile?" I thought she would have no idea whatsoever because frown is not a word that I believe she knows. She thought for a little while and then suddenly came out with "Owie". I was pretty impressed - that's some fairly good deductive reasoning right there!