Secondly, you know how in America we say, "Hi, how's it going?" or "Hi, how you doing?" and then keep walking like we didn't ask a question even though we totally did? Turns out - and I've heard this from three separate students now - the Chinese version of this goes, "Have you eaten?" or "Have you had lunch?" Can't really put my finger on the usefulness of this of this particular colloquialism excepting to get a very specific answer.