This one, or something very similar, happens fairly often.
A group of us, maybe 6 or 7 foreigners, were getting off a bus. A little kid waiting at the bus stop was quite excited to see so many foreigners, so he was jumping up and down and shouting.
Kid: 外国人！外国人！ (Foreigner! Foreigner!)
Me: 你好。你会说英语吗？ (Hello. Can you speak English?)
I hurried on because I was the one to get off the bus. As I walked away I heard:
(He said "Can you speak English?", why didn't you say "Hello"?)