When you compose a sentence, your subjects and verbs must agree. This means that you must use the correct verb form that matches the number of objects in your subjects. A singular subject, such as the dog must have a singular verb, such as eats to create the dog eats. Mostly, these types of errors are avoided in the case of singular subjects, but there are tricky constructions that confuse many people.
Two Subjects Connected by Conjunctions
Whenever you have more than one subject connected by and, your verb should take the plural form.
Jessica and her parents are going to the mall.
Because both of the nouns or pronouns in the subject are doing the action when joined with and, you need to use the plural verb, which is are in this example. If you are unsure if your sentence is correct, test it by substituting a pronoun in the place of the subject. Since there are multiple people in this example, use they. You wouldn’t say they is going to the mall, so you know you need the plural form are.
When you use the conjunction or with at least two singular nouns, your verb will also be singular, because the sentence implies that only one or the other of the subjects is doing the action.
Jessica or her mother is going to the mall.
To test in this case, you can just drop one of the nouns and see if the sentence is still correct. You wouldn’t say Jessica are going to the mall or her mother are going to the mall, so you need to use the singular verb.
The trickiest form of subject verb agreement occurs when you have singular and plural nouns in the subject of the same sentence. If the subjects are joined by and, you simply make the verb plural, since all the subjects are doing the action. If the nouns are joined by or, the verb agrees with whichever noun or pronoun is closest to it.
Either the boy or his parents are going to the mall.
Either the parents or the boy is going to the mall.
In these cases, as long as the verb agrees with the closes subject noun, you will be correct.
Doesn’t and Don’t
Some people have trouble with the contractions doesn’t, short for does not, and don’t, short for do not. Doesn’t should be used with singular nouns and pronouns, while don’t should be used with plural nouns and pronouns. There is an exception. The pronouns I and you always use don’t.
He doesn’t like baseball.
I don’t like baseball.
This can be confusing, but just remember the two exceptions, and you’ll get it right every time.
Phrases Between Subject and Verb
One of the most confusing parts of subject verb agreement is when a phrase comes in between the subject and the verb, because this seems contradictory to the rule that the verb agrees with whatever subject noun is closest. This is not a contradiction of the rule, because the phrase is not part of the subject.
One of my books is red.
Of my books is a phrase that describes which book the speaker is talking about, so the real subject of this sentence is one. This means that the verb, is, must agree with the subject one.
Typically, the subject is the noun that precedes of, which can make the subject easier to spot. There is an exception to this rule: Words that describe a portion are not the subject, and in these cases, the subject will follow the word of. In these cases, the verb must agree with the noun following of.
Twenty percent of those girls want to be doctors.
All of my homework is done.
Some of the dogs did not like her.
Either, Neither, Each, Each One, Everyone, Everybody, Anyone, Anybody, Nobody, Somebody, Someone, and No One
All of the above words are singular and should use a singular verb.
Nobody minds the noise.
Either is fine.
Always Singular or Plural
Some words always take a singular or plural form even if the word may appear to the be the opposite, and you just have to learn what they are.
Common singular words requiring a singular verb: civics, measles, news, mathematics. Most words concerning distances, amounts of money, and time periods will be considered singular when used as a collective unit.
Common plural words requiring a plural verb: pants, trousers, shears, scissors, tweezers.
There Is and There Are
Sentences that begin with there is or there are can be tricky because the subject actually comes after the verb. In these cases, the verb must simply agree with the subject noun after the verb.
There are many dogs.
There is a dog.
Do note that people commonly misuse the contraction form of this rule because it is easier to say there’s than there are. There’s should only be used in the singular form.
There’s a test today.
Collective nouns talk about more than one person, but are considered to be singular. Because they imply a singular subject, even though made up of many components, they should use singular verbs.
The team is travelling this week.
The family wants a new car.
Were and Was, Subjunctive Mood
When using were and was, you should stick to number agreement unless the sentence expresses a wish or is untrue. This is called the subjunctive mood, which indicates that a statement is imaginary, hypothetical, or contradictory. In subjunctive mood, use singular subjects with plural verbs. This rule also applies to other verbs besides was and were, though these are the most commonly confused.
I have asked that he sit in his chair.
I wish it were Saturday.