"Barrier" aka "The Barrier", a novella by Anthony Boucher, also the (unaccepted) answer to this question; first published in Astounding Science-Fiction, September 1942, available at the Internet Archive.
It's a time-travel story set on a dystopian future Earth.
The first difficulty was with language.
That is only to be expected when you jump five hundred years; but it is nonetheless perplexing to have your first casual query of: "What city is this?" answered by the sentence: "Stappers will get you. Or be you Slanduch?"
[. . . .]
No man alive in 2473 would have bestowed a second glance on the feloniously clad Brent, but in his speech, he realized at once, lay the danger. He pondered the alternatives presented by the stranger. The Stappers would get him, unless he was a Slanduch. Whatever the Stappers were, things that Get You sound menacing. "Slanduch," he replied.
The stranger nodded. "That bees O. K.," he said, and Brent wondered what he had committed himself to. "So what city is this?" he repeated.
"Bees," the stranger chided. "Stappers be more severe now since Edict of 2470. Before they doed pardon some irregularities, but now none even from Slanduch."
"I be sorry," said Brent humbly, making a mental note that irregular verbs were for some reason perilous.
Later the time traveler learns about the history of the dystopia:
In the middle of the twenty-fourth century, he learned, civilization had reached a high point of comfort, satisfaction, achievement — and stagnation. [. . .] Farthing had regularized the English language, an achievement paralleled by the work of Zinsmeister, Timofeov, and Tamayo y Sárate in their respective tongues.
[. . . .]
It was then that Dyce-Farnsworth proclaimed the Stasis of Cosmos. A member of the Anglo- Physical Church, product of the long contemplation by English physicists of the metaphysical aspects of science, he came as the prophet needed to pander to the self-satisfaction of the age.
He was curiously aided by Farthing's laws of regularity. The article, direct or indirect, Farthing had proved to be completely unnecessary — had not languages as world-dominant as Latin in the first centuries and Russian in the twenty- first found no need for it? — and semantically misleading. "Article," he had said in his final and comprehensive study This Bees Speech, "bees prime corruptor of human thinking."