As a young tabletop RPG nerd, I recall poring over the 4th edition Champions game book. Actually I suppose almost more of a tome, since at the time it was the thickest RPG manual I’d ever owned. Future me would laugh at that after seeing the 5th edition, but I digress. Champions used a point-buy system for character creation, from attributes all the way to defining your important interpersonal relationships. Anyhow, languages were bought on a one to five point scale. One point was being able to do basic things like ask where the bathroom is, two would give you fluency, three was “completely fluent with accent,” four was a native speaker, or at least being able to pass as one. But as I recall there was a five point level and it said something about having a command of idiomatic expression. At the time that puzzled me, not the least because teenage me had no idea what “idiomatic” meant. Now I do. The easiest way to explain it is as the little bits of slang people rattle off without thinking twice that only someone sharing their particular culture would understand. Could be an ethnic group, a nation, a region, or heck even a friend or family group. Some of them you might be able to figure out with enough fluency, like the English expression “you’ll catch more flies with honey than vinegar.” But if you’re not familiar at all with theater and someone tells you to “break a leg!” would you understand that they’re not inciting violence? In the recent Shang Chi Marvel movie there’s a moment where the nigh immortal Mandarin tells a village elder something which hits people familiar with Chinese culture hard. Closest English translation is, “I’ve eaten more salt in my life than you have rice.” This was not the translation subtitle given to English-speaking audiences who have no idea of the context and history behind that, but it basically is an expression meaning “I’m a lot older than you are, chump.” Hits like a truck if you get it, otherwise you can kind of understand the gist but not in the same visceral way. It’s like having to explain a joke. Playing the video game Control, there is a character you encounter who is an elderly Finnish janitor that speaks fluent English but sometimes sprinkles in idioms like “throw the spoon in the corner” or “you don’t have to run with your head as your third leg” and I had no frigging clue if those were actual sayings or he was just making shit up. Even then, when he says “the pensioner inside is starting to feel the band around his head” — is that a good thing or a bad thing? Well, he’s not making it up, turns out: https://www.reddit.com/r/controlgame/comments/d5f0ki/ahtis_idiomsfinnish_words_explainedtranslated/ Grasp of idiom is that highest point level because it depends on being so immersed in a culture you understand these things without even having to parse them out or look them up. But on the other hand, the Champions model still falls short because there are so many different subcultures. Context remains everything