Don LaFontaine was the voiceover artist famous for intoning the “In a world where … ” line in movie trailers. He died Monday, and it reminded me of an evening in 1984 when my college newspaper assigned me, for some reason, to cover a panel discussion by voiceover artists in New York. One of them was the man who was asking “Have you driven a Ford — lately?” in television commercials.

After the panelists had all spoken, the moderator cordially requested that audience members not use their questions as opportunities to audition — upon which one dulcet-toned person after another did precisely that for the next 45 minutes.

I will never forget one of them, a tall, leonine-looking black man of a certain age, with a chiseled jaw, in a tweed jacket and turtleneck, with a stentorian voice and a gorgeous British-tinged diction. He was clearly auditioning, but the script, so to speak, that he read from was, of all things, an indictment of Ford for the absence of black people in their commercials. “Are the-ah no bleck people driving Faw-uhd cahs?” he declaimed. He sounded like Franklin Roosevelt.

That man was the last in a line. In the more buttoned-up oratory culture of the old days, black people with a public presence often learned to speak in a “white” way in public, putting the kind of effort into this that we today associate with working on our bodies at the gym.

One of the oddest things about listening to a recording of Booker T. Washington, for example, is that he sounds like some white guy — despite having been born a slave. In Maya Angelou’s series of autobiographies, she often writes along the lines of “The drive to the airport was an adventure in motoring and a lesson in conversational dissembling,” which feels a little forced until you realize that in her era, there were people out there who thought black people really did all talk like Amos and Andy.

Nowadays fewer people labor under that illusion, and meanwhile formal oratory is long gone. As a result all Americans are more comfortable with at least a tincture of Black English in public speech. No black person under roughly 60 feels that having a black “flavor” at the microphone is a faux pas, and I cannot imagine a modern equivalent of Mr. “Faw-uhd Cahs.” (Who was that man?)

Ray Nagin of New Orleans, for instance, is certainly not one. As my friends at LanguageLog have noticed, in his statements about Hurricane Gustav, he has tossed off something most of us did not know was a word, adheed. “We thought there was a serious threat and I think most people will adheed to that.”

We can see what its meaning is in the sentence — no one paused and scratched their head while Mr. Nagin was speaking. The question is where it came from. It is a kind of train wreck between heed, adhere, and accede. There is a patch of meaning that all three words cover, plus an overlap in how they sound. A natural outcome in rapid, unplanned speech is a new word.

This is not a black thing, by the way. Adheed pops up all over the place from people of assorted hues. On line, you can read an Orthodox Jewish woman saying “She stubbornly refused to adheed to their request.”

But it’s not a word. Yes, I know — it’s not in the dictionary. But in the grand scheme of things, what’s in a dictionary is, in the sense of Plato’s cave analogy, mere shadows on the wall. In the eons that English has existed, little train wrecks have been the source of countless words we now think of as “real.”

Sweetheart began as sweetard, as in dullard. The “heart” part was a mistake, but because it made it into dictionaries, sweetheart “is a word.” Penthouse started as pentis; it sounded kind of like penthouse and soon, it was. Today, the “pent” part doesn’t make sense — how does a penthouse pent? But penthouse “is a word.” Or, what does a bridegroom groom? Certainly not his intended. Another little train wreck.

Mr. Faw-uhd Cahs would never have said adheed in public. But I’ll bet his children sound nothing like him, and I’m not sure I yearn for the language culture of their father’s era. Watching a language develop through time is like looking into a kaleidoscope — the theme is not merely additions, like blog, but unfettered mixture. You never know what’s coming. It’s fun. “Adheed” — who knew?

All of us are more part of this than we think. What’s the past tense of sneak? Snuck, now used by some of our finest writers, would have gotten you rapped on the knuckles by a schoolteacher just a century ago.

Mr. McWhorter is a senior fellow at the Manhattan Institute.