Grammar Girl here.
Today guest-writer Bonnie Trenga will help us talk about tricky sentences that make you question whether you should use a singular or plural verb.
Today we’re talking about a tricky kind of sentence that causes you to make a mistake with subject-verb agreement. As we all learned in school, a singular subject agrees with a singular verb, and a plural subject agrees with a plural verb. Sometimes, though, other parts of the sentence get in the way and confuse you. Here's an example of the kind of sentence we’re talking about: “The star attractions at the museum were the art.” Or should it be “The star attractions at the museum was the art”?
Defining Our Problem
Before we can answer the “were” or “was” question in the museum sentence, we need to define the problem. The source of the conundrum is what’s called a distracting predicate noun. A predicate is what provides information about the subject (1). In the museum sentence, the predicate noun is “the art,” a singular word. The subject, “the star attractions,” on the other hand, is plural. So should the verb agree with the subject or the predicate noun?
Solving Our Problem
Although this problem may seem complicated, it’s really not. It’s as simple as this: the verb agrees with the subject (2), not the predicate noun. Therefore, “were” is correct in the museum sentence because the subject is “the star attractions,” a plural noun:
The star attractions in the museum were the art.
Dorothy, don’t pay attention to the man behind the curtain, meaning don’t be distracted by the predicate noun. One grammar source calls this problem “false attraction to a predicate noun” (3).
Let’s try out one more example. What’s the right verb here:
The real draw of this restaurant is the desserts.
or
The real draw of this restaurant are the desserts.
Well, you know not to be falsely attracted by “the desserts,” which is the predicate noun. Instead, let’s identify the subject; it’s “the real draw,” which is singular. Therefore, the verb must be “is”:
The real draw of this restaurant is the desserts.
What comes after the “is” doesn’t matter.
Avoiding Our Problem
Sentences that contain a singular subject and a plural predicate noun, or a plural subject and a singular predicate noun, often sound awkward. Take these two examples: “Her best feature is her legs,” and “Dirty diapers are the worst part of parenting.” Although these sentences are grammatically correct, they could make readers do a double take.
If you want to avoid the problem, just rewrite your sentence. You could try to make both the subject and the predicate noun singular, or both plural; if that doesn’t work, you’ll have to change the sentence. As far as the legs sentence, you probably shouldn't write, “Her best features are her legs,” or “Her best feature is her leg,” so if you wanted to rewrite it, you would have to change it. Perhaps “She has great legs” would suffice.
As far as the dirty diapers sentence, you could say, “Changing dirty diapers is the worst part of parenting,” among other things.
Summary
In summary, sometimes subject-verb agreement gets muddied by other parts of the sentence, but don’t let yourself become distracted. Determine whether the subject is singular or plural, and then match up your verb accordingly.