Identify the subject of your sentence. In a simple sentence, the subject is the first noun that appears in a sentence. A noun is a person, place or thing. Examine the following sentence: "The ball rolls down the hill." The first noun in the sentence ("ball") is the subject of the sentence.
Identify the main verb of your sentence. A verb is an action or "being" word that tells the reader what the subject is doing. Examine the sample sentence from Step 1: "The ball rolls down the hill." The verb in this sentence is "rolls" because it tells the reader what the ball is doing.
Memorize the fundamental rules of subject-verb agreement. With practice, you can learn how to conjugate verbs like "to roll."
I roll
You (singular and plural) roll
He/She/It rolls
We roll
They roll
As you can see from the example, only the third person singular ("He/She/It") conjugation requires an "s." Learning subject-verb agreement is not too difficult, but it does require that you take the time to identify the subject and verb of your sentence. Practice!
Learn the indefinite pronouns. Indefinite pronouns present a special case for subject-verb agreement. They are called "indefinite" because the subject can be one of several possibilities. For example, "anyone," "each," "everyone," "no one" and "someone" are all indefinite pronouns. Each of these examples takes a singular verb. Other indefinite pronouns like "both" or "few" are obviously plural, and therefore take a plural verb. Finally, there is a group of indefinite pronouns that can take either a singular or a plural verb: "all," any," some," none," "half" and "most." If the pronoun refers to a unit or quantity (for example, a case of fireworks), then use a singular verb form. If the pronoun refers to individuals (for example, the different types of fireworks within a single case), then use a plural verb form.