Subjects and verbs must agree with one another in number. In the present tense, a singular subject takes a singular verb, and a plural subject takes a plural verb. Below is a list of common subject-verb agreement rules.
Singular verbs end in –s or –es.
Unlike nouns, the plural form of a verb is not made by adding an –s or –es to the ending. It's actually the opposite. For present-tense verbs, adding the –s to the end makes it singular. If the verb is plural, there is no –s ending used.
The driver speeds down the highway.
The girl stares at the cute guy.
The drivers speed down the highway.
The girls stare at the cute guy.
Compound subjects joined by "and" take a plural verb.
A subject that is made up of two or more nouns is a compound subject. When the parts are connected by and, the subject is plural, so it takes a plural verb.
Selena, Helena, and Mark ran the marathon.
The truck and the car have low mileage.
Subjects with singular nouns joined by or or nor take a singular verb.
Either the sour milk or the moldy cheese causes the fridge to stink.
Neither the black dress nor the pink gown is fashionable enough.
Subjects with a singular noun and a plural noun joined by or or nor take the verb that agrees with the closer noun.
Jalapeños or extra cheese makes pepperoni pizza even better.
Neither the supervisor nor his workers want to work overtime.
Subjects are not in modifying phrases.
When the subject and the verb are separated by other words or phrases, make sure the verb agrees with the subject, not with a noun within the phrase.
The paintings at the museum are strange.
Your baby-blue tuxedo with all the ruffles is tacky.
Don't let those phrases fool you.
Phrases using with, together with, including, accompanied by, in addition to, or as well do not change whether a subject is singular or plural. If the subject is singular, the verb should be as well.
Jane, as well as her sisters, enjoys punk music.
The cranberries, in addition to the broth, go in the stuffing.
Nouns with a plural form but with a singular meaning take singular verbs.
Nouns such as United States, civics, mathematics, measles, and news take singular verbs.
Mumps is a contagious disease that can be avoided with vaccination.
Physics sounds like a hard subject.
Nouns such as scissors, tweezers, trousers, jeans, and shears take plural verbs.
These nouns may appear to have a singular meaning, but each of these things is made up of two parts.
The shears are in the barber's hand.
The tongs have barbeque sauce all over them.
Collective nouns usually take singular verbs.
A collective noun has a singular form even though it refers to a group of individuals or things. Examples include army, audience, crowd, group, team, committee, class, and family. These nouns take a singular verb when the group acts as one unit.
The audience enjoys the long-awaited movie.
The crowd goes wild during a double play.
The town supports Mayor Bright.
However, a plural verb is used when people or things within a group act separately.
The broken-up band have solo careers now.
The family disagree about where to go on summer vacation.
If the subject follows the verb, the subject and verb should still agree.
When the normal subject-verb order is inverted in a sentence, the verb still agrees with the subject. For example, in sentences beginning with there or here, the subject follows the verb. Since neither there nor here is ever the subject of a sentence, the verb agrees with the noun that follows the verb.
There are many chores to do.
Here is the match to your other sock.
With words that indicate portions, look to the object of the preposition.
With words that indicate portions—percent, fraction, part, majority, some, all, none, remainder, and so forth—look at the object of the preposition (the noun following the of phrase) to determine whether to use a singular or plural verb. If the object of the preposition is singular, use a singular verb. If the object of the preposition is plural, use a plural verb.
Half of the car was covered in mud.
One-third of the sodas were peach flavored.