It’s not uncommon for two sounds in a word to trade places when someone speaks them, saying “aks” for “ask” or “revelant” for “relevant.” It’s common enough that there’s a word for it: metathesis.
Metathesis doesn’t just occur on an individual basis, though; there are words in which sounds have swapped places in the language itself over the years. Take “ask” for example. Although “aks” today is regarded as either a mistake or a dialect, it goes all the way back to Old English and even earlier. “Axian” is one of the ancestors of “ask.” And so is “ascian.” Basically, a couple of thousand years ago, some people said “ask” and some said “aks.” It’s only recently that we’ve gotten so fussy about language.
If you look at the origins of “bird”, it turns out that the word was originally “bryd”, with the “r” before the vowel. Same thing with “wasp”; it started out as “waps.” And although “revelant” is just something kids say when they’re learning the word “relevant,” there is a real word “rebellant,” which means “rebellious.”
A couple of times in English language history a word with swapped sounds has caught on and become a brand new word. That happened with “pattern,” which before the 1500s was just a mispronunciation of “patron.” Then there’s the case of a swapped sound resulting in another word that already exists, but means something utterly different. That’s what goes on with “cavalry” and “Calvary.” That particular confusion was so common in the British Army in the 1800s that their cavalry (which of course they actually had in those days, horses and everything) was nearly always pronounced as “calvary.”
An everyday response to hearing a word with swapped sounds is to refer to the word’s spelling. Depending on how irritated the listener is, this might even involve referring the speaker to the dictionary entry. But that’s just putting the cart before the horse; words were spoken long before they were spelled, and the way we spell them now isn’t necessarily the way it’s always been. And I bet it won’t be the last word — although the computers are increasingly in charge of that sort of thing, and compliance with a narrow notion of “correctness” is becoming mandatory.
