Agreement With Compound Subjects

Even if a subject doesn’t come breezing into the sentence with a string of modifiers trailing after it, it can still give us agree¬ment headaches if it’s what we call a compound subject—if it has more than one part. Do you say, Jack and he is going to the game, or, Jack and he are going? And if you’re not sure which of them will attend, do you say, Either Jack or he is going or Either Jack or he are going? Here are two rules to guide you:

First, the rule on subjects joined by “and”:
With one exception, all subjects joined together by the word “and” are considered plural, because they refer to more than one person or thing. So you’ll need to use a plural verb in order to have agreement.

In the previous example, the correct form would be Jack and he are going to the game. The exception is when the parts joined by “and” are meant to refer to the same person or thing, or to something commonly considered to be a unit. Two examples are cereal and milk is a typical choice for break¬fast and Her longtime nurse and companion (meaning that these are the same person) is coming to tea.

Now for compound subjects joined by “or” or “nor.” Un¬like subjects joined by “and,” the very role of “or” and “nor” is to separate, to tell us that it’s not both things, but one thing or the other that the verb applies to. So the rule is:

Subjects joined by “or” or “nor” are not considered as
a group, and the verb’s person and number should
agree with those of the subject’s individual parts.

There are three possible scenarios here. If both parts are singular, as in the subject Mary or Donna, then the verb is singular. If they’re both plural, as in the subject Neither the girls nor the boys, the verb is plural. And in really tricky sen¬tences where you have one of each, such as Either Tony or his daughters, the verb should agree with whatever part of the subject it’s closest to in the sentence; for example, either Tony or his daughters are but either the daughters or their father is. Let’s look at a few examples of common errors in agreement between compound subjects and their verbs.