It's pretty simple, right? A singular subject takes a singular verb, and a plural subject takes a plural verb. The dog is barking. The dogs are barking. Most of the time, we apply this rule without even thinking about it. But sometimes, we're stumped.

How Complicated Can It Be?

It can actually be a bit unnerving to consult a grammar guide for help with subject-verb agreement. In The Copyeditor's Handbook, Amy Einsohn lists no fewer than twenty-five types of problematic configurations, and in Grammatically Correct, Ann Stillwell devotes a full twenty pages to the subject (ahem, and verb): collective nouns; collecting noun phrases; each and each of;  fractions; one of those X who; time – the list of possible stumbling blocks is dizzying. (I nonetheless heartily recommend both books.)

Singular? Plural? How Can You Tell?

In all the complexity, though, the crux of the matter remains the same: Is the subject of the sentence singular or plural? Once that has been determined, the matter of the verb form falls into place quite easily. Which of these two sentences is correct?

                None of the policies has been successful.

                None of the policies have been successful.

If the subject is none, then the first version is correct, but if it’s policies, then the second version is right. So, is there a right or wrong answer here? In short: no.

Formal Agreement, Notional Concord, or Proximity?

Which version you choose depends on your approach. In the example above, the formalist would identify the subject as none and insist on the singular verb has. The notionalist would say that, since we’re clearly talking about more than one policy, the plural verb have would more accurately match the intended meaning.

The idea of proximity takes the idea of notional latitude a step further. Consider this sentence:

                Every Thursday, there is a free breakfast and snacks.   

In this instance, the verb is takes the form of the closest subject, breakfast, even though there’s another (plural) subject. Try out the sentence using are, and it “sounds wrong.” However, as the Merriam-Webster Dictionary of English Usage warns, “Proximity agreement may pass in speech and other forms of unplanned discourse; in print it will be considered an error.”

(Rant: Speaking of speech and other forms of unplanned discourse, there is no excuse for such monstrosities as There’s three ways to get there. Please plan your discourse!)

What If Nothing Sounds Right?

Some subjects, such as collective nouns, can go either way – singular or plural – and which verb you choose depends on the context. Don’t be put off by my earlier remark about the unnerving nature of grammar guides. Consulting them can be very helpful, as they may have examples similar to the sentence you’re trying to get right.

And sometimes, despite our best efforts to follow the basic rule of subject-verb agreement, nothing “sounds right.” In such a case, Amy Einsohn recommends rewriting to use a verb that is the same in both singular and plural (for example, an auxiliary verb such as can, may, should, or will).

Take Heart

English is a complex, live, and evolving language, so once you’ve done your best to follow the basic rule of subject-verb agreement, your ear may be the best guide of all.