Amanda Williams e-mails: “When describing what’s going to happen when we’re on the brink of dire circumstances, why do we write ‘if worst comes to worst’? Wouldn’t it make more sense to write ‘if worse comes to worst’, as in, things are bad and they might get worse?”

Idioms are like barnacles on the ship of language. Oftentimes they long outlive their original intent, confounding generation after generation seeking clarity in the linguistic shreds that they’ve inherited. “If worst comes to worst” is a case in point: it’s a proverbial idiom that has been around for more than four centuries in English, and yet it’s been an irksome source of puzzlement for about three centuries of that life span.

The earliest version of the idiom is in the form “if the worst come to the worst,” complete with definite articles and a subjunctive form of the verb come. In his 1596 pamphlet “Have With You to Saffron-Walden,” Thomas Nashe compared death by drowning to death by burning: “If the worst come to the worst, a good swimmer may do much.” Since then, the same turn of phrase has shown up in the work of John Dryden, Henry Fielding, Charles Dickens and Charlotte Brontë.

The idea encapsulated by the original idiom is that of a worst-case scenario brought to life. “Come to” here means “result in” (as in come to nothing), so the phrase describes the worst thing in theory turning into the worst thing in actuality. A somewhat similar expression that didn’t have the same historical staying power is “when all comes to all,” meaning “when all is said and done.”