General Rule: Singular subjects require singular verbs, while plural subjects require plural verbs.

This rule is easy to work with when the subject and verb in the sentence are clear. For example, consider the following sentences where finding the errors is not difficult:

  • Stars recedes from the center of the universe.
  • Baseball players has to train.
  • The nineteenth century were an important time.

There is no question that these sentences are incorrect as written. However, when modifiers and prepositional phrases are added to the sentences, the problems with subject-verb agreement may become harder to spot. Consider the sentences again:

  • The stars, which appear motionless despite moving at a tremendous velocity, recedes from the center of the universe.
  • Baseball players and other athletes who train themselves to perform at high levels for short periods of time has to train their bodies to exert themselves in quick bursts.
  • The nineteenth century, which saw the re?nement of such crucial liter-ary forms as the novel, the short story, and the serial, were important in the evolution of literature.

Now that the subject and the verb are separated from each other it becomes somewhat tougher to spot the problems in subject-verb agreement. However, by analyzing the sentence and breaking it down to a subject and a verb, the error becomes apparent again.

Some sentences have more than one verb and every verb in a sentence has a subject. In terms of analysis, the task is still the same to isolate the verbs and their subjects and ignore the modi?ers and prepositional phrases that obscure the relationship between the subject and the verb. For example, in this sentence:

  • Developments in neuroscience are challenging long-held beliefs about how people process information during stressful situations. 

There is a main subject, developments, and its verb, are challenging. But the prepositional phrase about how people process information also has a verb, process. The subject of this verb is people.

Common Mistakes in Subject Verb Agreement

Compound Subjects

Compound subjects use conjunctions such as and, neither…nor and either…or . Singular subjects joined by the word and are always plural. When using neither…nor or either…or , the verb must agree with the noun closest to the verb.

Collective Nouns

Collective nouns treat entities made up of many parts as a single unit and therefore, they are singular. Examples of collective nouns include: the jury, the corporation, and the team. Some words that end in s appear to be plural but are actually collective nouns. For example, Mathematics is singular.

Indefinite Pronouns

Indefinite pronouns refer to an unknown or unidentified person or thing. Indefinite pronouns include: everyone, anyone, anybody, everything, nothing, somebody, someone, and each. Most indefinite pronouns are singular. There are only a handful of plural indefinite pronouns. These are: both, few, many, and several. Some indefinite pronouns may be either singular or plural. These include: all, any, more, most, none, and some. These are singular when the noun they refer to is singular and plural when the noun they refer to is plural.