Grammar Tips: Subject–Verb Agreement

An important part of writing a grammatical sentence is making sure that the subject and verb in a sentence agree. In the following, we’ll take a look at some of the basics.

The Basics of Subject–Verb Agreement

In the present tense, subject–verb agreement requires using singular verbs with singular subjects and plural verbs with plural subjects. In this context, the “subject” is the person or thing in the sentence performing the action, while the verb is the action being performed:

In the simple past tense, though, there’s usually no difference between singular and plural verbs:

Compound Subjects

Subject–verb agreement becomes more complicated when using a compound subject. When two subjects are joined with the coordinating conjunction “and,” we always use a plural verb:

Bob and Cheryl are going to the game.

However, when using “either/or” or “neither/nor,” whether to use a singular or plural verb depends on the noun nearest to it:

Singular: Either the girls or the boy is going to the game.

Plural: Neither the boy nor the girls are going to the game.

In the above, we use the singular “is” when the singular noun “boy” comes after “or,” but the plural verb “are” when the plural noun “girls” comes last.

Parenthetical Statements

One common mistake with subject–verb agreement occurs when a parenthetical statement appears between the subject and the verb:

The man, in the company of his dog, goes for a walk.

Here, we use the singular verb “goes” because the dog is part of a parenthetical clause (i.e., within commas), not part of the sentence subject.

If we rephrased this so that the dog was part of a compound subject, we would use the plural verb “go” instead:

The man and his dog go for a walk.

But when an additional person or thing is mentioned parenthetically, the verb should always agree with the subject of the main clause.

Collective and Mass Nouns

Another potential confusion relates to the use of collective nouns. In American English, collective nouns (i.e., nouns that refer to a group of things) typically require a singular verb. However, you can use a plural verb with a collective noun if the members of the group are acting as separate individuals:

Acting Together: The team is playing to win!

Acting Separately: The team are arguing with each other.

Here, we use the singular verb “is” to describe a team that is working together. But we use the plural verb “are” when the players are acting as individuals.

Mass (or “non-count”) nouns are similar, since they take singular verbs despite referring to a mass substance (e.g., “milk” or “sand”):

The milk is going sour.

The sand stretches on for miles.

Here, it doesn’t matter how much we’re discussing (e.g., a small or large amount of souring milk), we always use the singular  form.

Some Exceptions

As usual in English, there are exceptions to the rules above. The first-person “I” and the singular second-person “you,” for example, reverse the usual rules in the present tense (e.g., we say “I sing” not “I sings,” even though “I” is singular and “sing” is usually a plural verb).

Auxiliary (or “helper”) verbs (e.g., “is”/“are” or “has”/“have”) also cause trouble, since they often change depending on whether the subject is singular or plural when using a past participle (e.g., “The boy has finished his homework” vs. “The boys have finished their homework”).

And since the rules do vary depending on how a sentence is constructed, it pays to be careful with subject–verb agreement! Having your work proofread is a good idea if you’re not confident about this aspect of grammar.