Is “took a turn for the worst” correct or a malapropism?

The original English idiom is “took a turn for the worse” (with worse, the comparative), used when a situation gets worse. Many speakers, including Australians and Americans, now say “took a turn for the worst” (with worst, the superlative). It’s technically a malapropism, but so widespread in spoken English that grammarians have given up correcting it.

This clip uses the worst version in an Australian teen-pregnancy story, dropped in matter-of-factly. That’s where the malapropism feels most natural: high-emotion personal storytelling, casual conversation, no one reaching for the textbook form. Both forms now coexist, with worst slightly more common in casual storytelling.