It isn’t easy to admit being wrong in front of thousands of readers, but Ben Yagoda took it on the chin. He had written a sentence containing this clause (which I mark with the asterisk that linguists use to signal an ungrammatical string of words):

*The meaning of words inevitably and perennially change.

I found it instructive: It reminded me of one of the worst features of the grammar advice so many universities hand out to students.

Certainly it was ungrammatical. The subject noun phrase (NP) is the meaning of words. Its head is the singular noun meaning, so it is a singular NP. There is a complement phrase of words, containing a plural noun, but that’s a distraction: It’s not the one that determines the number of the NP and the agreement on the verb. The verb should have been in its third-person singular agreement form, changes, but instead it shows the plain present form, change. (An alternative would have been to make the subject NP plural, yielding a different and perhaps preferable way of saying the same thing: The meanings of words inevitably and perennially change.)

Ben had apparently fallen victim to the distracting lure of a noun that was not the right one to determine the verb agreement, a noun that was closer to the verb and thus momentarily more salient. Speakers and writers of human languages have been committing such errors of performance for centuries, and doubtless (though evidence is hard to come by) millennia.

But it is crucial to see that it exemplifies a slip-up in execution during the writing process, not a mistaken conception of what the rules are. And I think we should keep that in mind when reflecting on some of the items on those lists of “common errors” that are so often handed to students.

I wrote about a plangent example here on Lingua Franca, in “Lying About Writing” (November 14, 2013), in an irritatingly silly one-sheet list (plagiarized from William Safire) where each entry states a “common error” in a form that exhibits that error. Item 1 was: “Verbs has to agree with their subjects.”

Yes, of course; but that is useless advice to anyone who knows the language natively, for two distinct reasons.

The first is that the rule to be followed is actually complex and subtle. You need some technical grammatical terms (“head noun,” “tense,” “main verb,” “subject,” etc.) to state or understand even an approximate version. A rough approximation of the rule would be this:

But there are many complications. Some noun phrases have the form of a plural noun but are singular (Corn flakes is my usual breakfast). Coordinate subjects with or have an unclear status (?Anna or possibly the Murphy brothers is/are dealing with it). Partitive noun phrases with nouns like group or number or pack are a matter of significant dispute: Should it be ?A pack of dogs was terrorizing the neighbourhood, or ?A pack of dogs were terrorizing the neighbourhood, or are both OK? (Both pack of dogs was and pack of dogs were occur thousands of times on the web in apparently literate prose.)

And so on. The bottom line is that it is tricky even to say in full what the rules entail.

But the second and much more important point is that the difficulty generally lies in the performance, so giving a general instruction to follow the rules is like telling a failed hurdler after a bad crash: “Listen, Bob, you should make sure that you lift your feet high enough to get over the hurdles without hitting them.”

Bob could be forgiven for snarling back that he doesn’t need to be told that he should be going over the hurdles without knocking them down. His problem is that he can’t always judge and execute the leap just right. If he was able to guarantee to follow the pointless advice, there would never have been a crash in the first place, which is precisely why the advice is pointless.

We’re being just as stupid when we tell students in general terms to please make their verbs agree with their subjects. First, that’s not an adequate statement of what they have to abide by; and second, people slip up at the implementation stage if the wrong noun momentarily catches their eye. Yes, such slips are grammatical errors, and we should teach students to edit their grammar. But even a fine writer like Ben Yagoda can occasionally hit one of the hurdles with a trailing foot. That doesn’t mean we need to hand him a piece of paper telling him that English has subject-verb agreement.