It's not every day that I pick on others' language errors.

Regular readers of this column know that, on the contrary, I think criticizing another person's grammar or usage is misguided. Worse, nine times out of 10 the would-be grammar cop has his or her facts wrong, perpetuating the very superstitions that give real grammar a bad name.

But a mistake I saw on CNN's website recently is bringing out the critic in me.

Maybe it's because I've seen a rash of errors lately on news websites. Yahoo Finance, for example, shows its lack of editing savvy — or perhaps its lack of editing — on a regular basis. And though I don't visit CNN's site much, it seems to have more than its share of errors too.

Honestly, if you were to remove all identifying visuals from CNN's news content and then do the same for the Associated Press, I bet I could tell you which was which based simply on the number of editing errors and the assumption that CNN makes more.

The mistakes I'm talking about aren't earth-shattering. They may not make a difference to most readers. But they suggest something's not right in the copy editing department.

The CNN mistake that was my tipping point appeared in a story about the president making an unannounced stop at a D.C. restaurant for a burger. Here was the first sentence of that article: "It's not everyday you get to have lunch across the table from the President."

The mistake in this sentence may not be so bad for the reader. There's no chance that this error could create confusion. But in my experience, knowing the difference between "everyday" and "every day" is Copy Editing 101. It's among the first things a new editor learns. And though I've met copy editors of all experience levels, I don't think I've ever met one who didn't know that the one-word "everyday" is an adjective.

Like other adjectives, "everyday" modifies nouns. "This store offers great everyday prices." "Their everyday lives are very tranquil." "This is an everyday thing for me." In these correct examples, "everyday" modifies the nouns "prices," "lives" and "thing," respectively.

"Every day" is different. It's a noun phrase. Like other noun phrases, it can do different jobs. Often, a noun phrase is the subject of a sentence — "Every day is a gift" — in which it performs the action in the noun. Noun phrases can also function adverbially, answering the question "when" or "where." In "He visits Thursday afternoons," the noun phrase is functioning adverbially. In "He visits every day," the noun phrase is, once again, functioning adverbially.

That fact doesn't change when you tweak that sentence a bit to get "It is every day that he visits." The term is still answering the question "when," which is simply not a job an adjective can do. So you can see how the adjective "everyday" was wrong in the CNN sentence because adjectives don't work as adverbials.

The easy way to remember this — the way most copy editors understand it — is simply that the one-word "everyday" only works immediately before a noun — "prices," "lives," "thing" and so on. In all other instances, the two-word noun phrase "every day" should be used.

True, this CNN error could have been made out of haste instead of ignorance. A typo a few sentences later, where the last name "Lichens" begins with two capital letters, "LIchens," suggests that haste was a factor. But somehow, that doesn't make me feel any better about CNN's editing standards.

JUNE CASAGRANDE is the author of "The Best Punctuation Book, Period." She can be reached at JuneTCN@aol.com.