Subject-Verb Agreement

The subject and verb of a sentence must always agree in number: a subject that is singular should go with a singular verb; a subject that is plural should go with a plural verb. Matching the subject and the verb is important because it prevents the reader from confusing which noun is the subject.

This is a simple sentence, and it is clear to the reader that the subject of the sentence is “girl.” The singular verb “is” agrees in number with the singular subject “girl.”

However, this is not always obvious for more complex sentences. Take for example the following.

Here, the subject is “Sample 1,” but if the sentence used the plural verb “were,” it would be easy for the reader to think that the subject is not only sample 1 but also sample 2 and 3.

Subject-verb pair examples

A sentence can have more than one subject per verb. When two or more subjects share the same verb, the subjects are joined with the conjunction “and” or “or.” Subjects joined by the conjunction “and” are always used with a plural verb.

In contrast, singular subjects joined by the conjunction “(either…)or” are used with a singular verb.

The same applies to singular subjects joined by the conjunction “(neither…)nor.”

However, if the joined subjects are plural, a plural verb must be used.

Occasionally, a compound subject may contain both singular and plural nouns. In this case, the verb should match the form of the noun closest to it.

The singular verb “need” is used here because “components” is a plural noun.

More examples of subjects connected with “and”

Subjects that are joined by “and” are used with plural verbs.

More examples of subjects connected with “(either…)or” or “(neither…)nor”

Singular subjects that are joined by “(either….) or” or “(neither…) nor” are connected with singular verbs.

Plural subjects that are joined by “(either…) or” or “(neither…) nor” are connected with plural verbs.

Compound subjects that contain both singular and plural nouns are connected by verbs that match the noun closest to it. When one of the nouns connected by “or” or “nor” is plural, the verb must be plural, and the plural subject should be placed next to the verb.

Separated subject and verb

Many sentences have phrases or clauses that separate the subject from the verb. This can make it difficult to identify the subject. Take for example the following two sentences

Which sentence is correct? The answer is b. This is because the subject of the sentence is “studies” not “subject.” Using the correct verb form can help the reader better identify the subject of your sentence.

By using the correct plural verb, the second sentence makes it clear that “derivatives” is the subject.

Other connectors: “along with,” “as well as,” “in addition to”

Phrases such as “along with,” “as well as,” and “in addition to” are not conjunctions, but they do act as connectors. As mentioned above, subjects joined with the conjunction “and” are always used with a plural verb. This is not the case for “along with,” “as well as,” and “in addition to.”

These connector phrases differ from “and” in that they do not create a compound subject. In the above sentences, the subject is “composite C” — not “composite C, along with composite A,” “composite C as well as composite A,” or “composite C, in addition to composite A.”

Another common confusion is whether indefinite pronouns, such as “anything,” should be used with singular verbs or plural verbs. Some indefinite pronouns are always treated as singular while others are always treated as plural. A few of these pronouns may be treated as either singular or plural, depending on the sentence. Common indefinite pronouns: all, any, anything, anybody, anyone, anywhere, every, everything, everybody, everyone, everywhere, some, something, somebody, someone, somewhere, none, nothing, nobody, nowhere, more, most, another, each, one, both, either, few, many, several

Most indefinite pronouns are treated as singular. “Every,” “another,” “each,” and “one” as well as all indefinite pronouns that end with “thing,” “body,” “one,” or “where” are used with singular verbs.

On the other hand, “both,” “few,” “many,” and “several” are treated as plural.

A few indefinite pronouns are treated as either singular or plural depending on the sentence. These are “all,” “some,” “any,” “none,” “more,” “most,” and “either.” See the following sentences using the indefinite pronoun “some.”

In the first sentence, “some” refers to the “samples,” which is plural and should be used with a plural verb. In the second sentence, “some” refers to the “sample,” which is singular and should be used with a singular verb.

There are sentences for which the subject follows the verb rather than vice versa. This is true for sentences that begin with “there” or “here” as well as sentences with an inverted sentence structure.

As can be seen from the examples above, the same rules of subject-verb agreement apply to sentences with subjects that follow the verb.

Sometimes the subject of a sentence may be a number or quantity. This is particularly common in academic writing, since numerical values are typically important to scientific research. The verb form that should be used with numerical subjects depends on what the number is referring to.

“67%” is referring to the “samples,” which is plural. Therefore, it should be used with the plural verb “were.” “80 cm,” on the other hand, refers to “electrical tape,” which is singular and thus should be used with the singular verb “was.” The same applies to subjects that are proportions.

If the subject is a unified numerical quantity of something, it should be treated as singular.

Collective nouns are nouns that refer to a unified group of people, animals, or things. The verb form that should be used with such nouns differs for US and UK English. Collective nouns are typically treated as singular in US English but as plural in UK English.

A flock is a group of birds. According to US English conventions, “flock” should be used with a singular verb. On the other hand, UK English conventions dictate that “flock” be used with a plural verb. This is because US English places emphasis on the unity of the flock while UK English places emphasis on the many birds that make up the flock.

“Emphasis” is the key word here, as the content of a sentence can determine whether a collective noun is treated as singular or plural.

Uncountable nouns are of abstract concept or general terms and thus cannot be counted. Examples of uncountable nouns: research, information, progress, equipment, furniture, luggage, flour, cement. Uncountable nouns are always used with singular verbs.

The rule for acronyms and abbreviations is simple: check what term(s) the abbreviation/acronym is short for. First, determine whether the full version is singular, plural, compound, or collective and then apply the relevant rules accordingly.

“SSD” stands for “solid-state drive,” which is singular and should be used with a singular verb.

“BCS” stands for “breast cancer survivors,” which is plural and should be used with a plural verb.