Every year when I was a kid, we spent a good portion of the summer in South Carolina with our extended family. We'd drive up to my grandmother's house and stay a while with her, visiting some cousins in a different part of the state occasionally. One summer, my aunt and uncle had a foreign exchange student with them. And she was there while we were visiting for a few weeks. And due to my cousin's accelerated, South Carolina-accented speech, the Spanish girl who barely spoke English (I think her name was Olga) got confused a lot. So I took it upon myself to translate his fast, Southern English into slower, unaccented English to keep her from feeling lost. I didn't want her to be completely confused the whole time she was there.
So I turned into her English-to-English translator during that time. And she got in the habit of looking at me whenever she needed something explained (or simply slowed down as was often the case). Well, one day we were planning a trip into Atlanta to see a baseball game, and someone mentioned taking a bus instead of parking downtown. And Olga looked at me and said, "A bus?"
This is where there was some confusion. When she said that, she meant it as, "We're taking a bus? Why would we need to take a bus if everyone here has their own car?" But what I took it to mean was, "A bus? What in the world is a bus?! I've never heard of such things!"
So I said, "A bus? Well… how do I explain? Okay, it's basically a really long car with LOTS of windows." And when I said "really long car" I put my arms really wide and raised my eyebrows as high as I could.
So then she had to explain to me that she knew what a bus was. They have buses in every country, and it's a fairly common English word. And then she explained that she wanted to know why we were taking a bus. Then, the little Spanish girl who barely spoke English did her first truly American thing. She shook her head and rolled her eyes at my ignorance. And though it really hurt my feelings, I couldn't help but feel proud of her for learning to judge people when they're stupid.