Idiom Is a Trap for the Careless Writer

A line about a man whose "liver had gone black with worry" felt like the sharpest image in the chapter when I wrote it in Darija, and read as a dead cliche the moment I moved it into French, where the liver has been standing in for worry since before either of us was born.

The idiom is not wrong in either language. It is simply older in one than the other, worn down by use the way a step gets worn down by feet until the edge disappears. In Darija the phrase still had texture for me, because I do not read enough of it to have gone numb to it. In French, "se faire un sang d'encre," the equivalent expression, has been sitting in newspaper columns and grandmothers' warnings for so long that no reader registers it as an image anymore. It registers as a sound: worried, nothing more, the picture behind it long since worn smooth.

The idiom half-life

Every idiom has what I have started calling a half-life: the amount of exposure before a phrase stops producing an image in a reader's mind and starts producing only its dictionary meaning. A brand new idiom, or one borrowed from a language your reader does not use daily, still has its picture attached. An idiom your reader has heard three thousand times has none. The mistake careless writers make is judging an idiom's freshness by their own ear, in whichever language they thought of it in, rather than by their reader's actual exposure to it, which is a completely different number.

I learned to test this by asking a specific question before keeping any idiom past a first draft: could I replace this exact phrase with its literal dictionary meaning and lose nothing but the idiom's decoration? If yes, the idiom's half-life has expired for this reader and it is doing no work beyond filling space where an actual image should be. "His liver had gone black with worry" fails that test for a French reader instantly, because "worried sick" and the liver phrase carry identical information now. It does not fail the test for an English reader, who has likely never seen the liver used this way and will still form a picture, briefly grotesque, that a French reader stopped forming decades ago.

Why this trips up multilingual writers specifically

A writer working in only one language eventually develops an ear for which idioms in that language are dead, mostly because they have read enough contemporary prose in it to notice which phrases keep showing up in the throwaway sentences of tired journalism. A writer moving between languages loses this calibration precisely where they need it most, because an idiom that sounds vivid in your second or third language often sounds vivid only because you have not logged enough hours in it to have worn the image down yet. The freshness you are hearing is a fact about your own limited exposure, not a fact about the phrase.

The counter worth taking seriously

The counter here is that idioms exist precisely because they compress a complicated feeling into a single recognisable unit, and refusing all of them in the name of freshness leaves you writing around ordinary human states with clumsy invented phrases nobody will parse quickly. That is a real cost. A reader who has to decode a brand new image for "worried" every time a character worries will tire faster than one who gets the familiar phrase once in a while. I do not avoid idiom entirely. I ration it, deliberately, to the two or three moments per chapter where I actually want a reader to slow down and notice an image rather than skim past a feeling, and I let the rest of the prose move at ordinary idiomatic speed.

What the test buys a translator specifically

For a translator this test matters twice over, once for the source and once for the target, because an idiom fresh in the original may be dead on arrival in the target language, or the reverse, dead in the original and accidentally vivid once translated. Checking half-life in both languages before deciding whether to keep, replace, or invent an idiom is the only way I know to stop a sentence's temperature from changing without anyone intending it to.