The simple definition of subject-verb agreement is that when the noun is plural, the verb must also be plural. Conversely, when one is singular, the other one must be singular. There are some variations on this rule when dealing with compound subjects.
- When the compound subject is two or more singular nouns connected by "or" or "nor", the verb should be singular: An article or a book on that topic is in the library.
- When the compound subject is two or more nouns or pronouns connected by "and", the verb should be plural: Sally and Tom are running late for the meeting.
- When a compound subject contains a singular and a plural noun or pronoun connected by "or" or "nor", the verb should agree with the subject that is closest to the verb: The CEO or his vice presidents approve the projects.
Another common problem is when the writer confuses the subject of the sentence with a phrase that comes between the subject and the verb. For example: One of my goals is to be on time to work. The word "goals" is plural, but the subject of the sentence is "one," which is singular; therefore, the verb must agree with the singular subject.
Other examples of subject-verb agreement arise when the writer is not completely sure which form of a verb should be used if the word appears to be plural.
- Civics, measles, and news are all singular nouns that require singular verbs.
- Pants and scissors, while referring to one object, have two parts, therefore, they are considered to be plural and require plural verbs.
- Words such as team, family, and committee are called collective nouns and are treated as singular nouns requiring singular verbs.
- If the subject is singular, followed by a phrase starting with in addition or including and a plural noun, the verb is still singular. For example: The CEO, in addition to members of the board, is going on the trip.