An idiom is, by one definition, "an expression whose meaning cannot be inferred from the meaning of its parts." Or, as Jag Bhalla, author of I'm Not Hanging Noodles on Your Ears, described them in the book, idioms are "cryptic little word puzzles" or even "fossilized metaphors"—preserved figurative expressions that have outlasted their original context. One example: "To pull out all the stops" now refers to making "every possible effort," even though few people who do so are playing an organ with its "stops" out to activate all the pipes, as Bach reportedly did in helping give the phrase its original meaning.

"It's just fascinating that every culture has them," Bhalla told me, notwithstanding the fact that idioms are "often the least logical way to communicate a thought." So what's the point of these expressions? Psychologists, linguists, and anthropologists have all studied the topic, but there's one clue about the function of idioms contained within the word "idiom" itself. As Bhalla wrote in his book:

The word idiom has the same root as idiosyncratic and idiot: idios, Greek for ‘of one’s own’ or ‘private.’ The original meaning of ‘idiot’ was someone who was not interested in public affairs (considered a key duty in ancient Greece). Similarly, idioms are a form of private expression, private to the in-group, that is.  

That's why the following quiz of idioms from 11 different languages is a little unfair—it's difficult to be in 11 in-groups simultaneously. English itself isn't one big in-group. I take it for granted that "killing two birds with one stone" is, in English, about efficiency rather than a terribly cumbersome technique for murdering fowl. But why do British English-speakers seem to think "Bob's your uncle" means "that worked well"? What's Bob got to do with it?

I compiled the following quiz with help from Bhalla and his book, plus friends and colleagues who have used or been confused by the following phrases, sometimes simultaneously, at home or in their travels. It's a tiny snapshot of the essential mystery and goofy poetry of the world. Good luck and, as the Germans say for some reason, may you live like a maggot in bacon.