Authors, Writers, Publishers, and Book Readers
The basics of subject–verb agreement. The number of the subject determines the number of the verb. In other words, if the subject is plural, the verb, too, must be appropriate for plural subjects. The following samples demonstrate singular and subject verbs.
Singular Noun Samples: cat, I John, flower
Plural Noun Samples: cats, we, John and Bob, flowers
Subject–Verb agreement causes problems only in the present tense. Unlike verbs in other tenses (e.g., past tense, future tense), present tense verbs change according to whether the subject is singular or plural.
First person (refers to self)
Singular: I eat
Plural: We eat
Second person (refers to reader or listener)
Singular: You eat
Plural: You (all) eat
Third person (refers to someone else)
Singular: He / She / It / Who eats
Plural: They eat
In the third-person singular, the present tense verb has an “S.” Thus, if the subject of a verb can be replaced by he, she, it, or who, the present tense verb has an “S.” Remember: “S” for “Singular.”
Once you determine the subject for a verb, decide whether the subject refers to a single person or thing or to more than one person or thing. Examples A.1a and A.1b have singular and plural subjects, respectively. The subjects are underlined, and the verbs are italicized.
Example A.1a, singular subject: “The principal investigator leads the research team.”
Example A.1b, plural subject: “The principal investigator and finance director lead the team.”
Subject–verb agreement with “to be” verbs. In the present tense, “to be” verbs include the following.
Singular: I am
Plural: We are
Singular: You are
Plural: You (all) all
Singular: He / She / It / Who is
Plural: They are
As seen in the samples above, if you can replace the subject with he, she, it, or who (singular subject), use is for the verb. If you can replace the subject with they (plural subject), use are for the verb. Again, remember: “S” for “Singular.”
Subject–verb agreement with and and or. The word and will indicate a plural subject, and the verb will also be plural. In example A.2a, and indicates that the subject includes more than one person, i.e., is plural.
Example A.2a: “The principal investigator and the finance director lead the team.”
The word or will indicate a singular subject if both parts of the subject are singular, and the verb will also be singular. In example A.2.b, the subject is either one principal investigator (single person) or one finance director (single person).
Example A.2b: “The principal investigator or the finance director leads the team.”
However, if the subject includes or and either part of the subject is plural, the verb will be plural. In example A.2c, one part of the subject is research directors, which is plural.
Example A.2c: “The principal investigator or the research directors lead the team.
Subject–verb agreement with either. When the subject includes either, the verb may be singular or plural. If either refers to a pair of people or things, the verb will be singular. In this case, either indicates either one, which is singular. In example A.3a, either refers to a pair of children.
Example A.3a, pair: “If either of the children has symptoms, bring him to the clinic.”
If either is followed by or, use the same guidelines as for or. If both parts of the either / or are singular, use a singular verb, as in example A.3b. If either of the two parts is plural, use a plural verb, as in example A.3c.
Example A.3a, singular either/or: “Either the older or middle child is likely to display symptoms.”
Example A.3b, plural either/or: “Either the older child or both younger children are likely to display symptoms.”
Subject–verb agreement with any and all. The word any may have a singular or plural verb. If any refers to any one, the verb will be singular, as in example A.4a. If any refers to more than one, the verb will be plural, as in example A.4b.
Example A.4a, singular any: “If any flight lands on time, notify the people on the waiting list.”
Example A.4b, plural any: “If any flights land on time, notify the people on the waiting list.”
The word all follows the same guidelines as any. If all refers to a singular noun, the verb will be singular, as in example A.5a. If all refers to a plural noun, the verb will be plural, as in example A.5b.
Example A.5a, singular all: “All the salt dissolves in the solution.”
Example A.5b, plural all: “All the salt crystals dissolve in the solution.”
Subject–verb agreement with every, everyone, and everything. Every, everyone, and everything are singular words. Although they may refer to many people or things, these words refer to them as individuals. As such, they require singular verbs, as in example A.6.
Example A.6: “Prior to opening the business, ensure that everyone understands his or her duties.”