Between you and I, it does. But when I put the question to a friend recently, I was answered with a demurral. “Not so much,” they said.

If you’ve read this far, you may have flagged two lapses in grammar and word usage. “Between you and I” sounds right but is dead wrong. And, given that I was chatting with one friend, and not an army of them, there was no “they” to respond to my question.

Writing recently in the New York Times about the Walter Isaacson biography of Steve Jobs, Joe Nocera referred to “the enormity of Jobs’s accomplishments.” He meant “enormity” in a good way, of course, as a synonym for “impressive scope”—or “enormousness” if you will. But he was in error: The word has nothing to do with size. An enormity, according to the dictionary, is “an abomination, an act of great wickedness.”

All of which begs the original question: Does proper English still matter?

Language evolves constantly, and many words and usages that would once have brought a wrist-slap from pedants and grammarians eventually find their way into acceptability. Some still reject “hopefully” as a stand-in for “it is hoped,” and insist that its only proper meaning is “full of hope”: He gazed hopefully across the room at the green-haired girl with the accordion tattoo.

That was once true. It isn’t now. “Hopefully” is a classic example of what lexicographer Bryan Garner calls a “skunked” word—one whose meaning has expanded or changed, but tends to annoy traditionalists even when used correctly. Hopefully, they’ll get over it.

These issues interest me as a writer, editor and marketing communications professional; they’re also at the heart of the messaging we create for clients, which should be clear, simple and conversational. The problem is that grammatical correctness is often the enemy of clarity and simplicity. Consider the noun-pronoun disconnect in the sentence “We help each client achieve their objectives.” Replacing “their” with “his” is grammatically correct but male-centric. “His or her” is also acceptable, but repeat it too often and it begins to sound clunky.

HNW copy chief Kevin Davies used to flag noun-pronoun glitches as a matter of course. Now he’ll occasionally let them stand. “It’s a matter of time before linking ‘their’ to a singular noun will be considered correct,” he says. Same for words like “media” and “data,” which are plural forms of “medium” and “datum,” respectively. But treating them as singular—“The media reports that the data is inconclusive”—is standard usage in many circles. Davies is fine with that too.

“When I use a word,” says Humpty Dumpty in Through the Looking Glass, “it means just what I choose it to mean—neither more nor less.” His thinking is scrambled: Language is mutable but it isn’t anarchic. Rules apply, whether you’re writing an op-ed column or a product brochure. At this point in time, enormity does not equal enormousness. And to “beg the question” isn’t to “raise the question,” notwithstanding its deliberately wrong-headed use above.

Someday, perhaps. But not today. Between you and me, there definitely is such a thing as proper English. And, yes, it does matter.