Grammar Lesson: Compound Subjects

A subject is the doer of the action in a sentence. A compound subject has more than one subject.

In each of these sentences, the compound subjects are underlined.

The cat and the mouse ran around the room.
Neither the cat nor the mouse heard him.
Both the youngsters and the adults enjoyed square dancing.

Here are two important rules when working with compound subjects. You will be introduced to several other rules on another page.

• Rule #1: Singular subjects joined by and usually agree in number with a plural verb.
  This plant and a large tree were in the photo.
  The older boy and his companion have the boxes of fruit.
  His dad and my brother are on the same work crew.
• Rule #2: Compound subjects that have a single entity agree in number with a singular verb.
  Bacon, lettuce, and tomato is Mitt's tastiest sandwich. (Bacon, lettuce, and tomato are a single entity here.)
  Chutes and Ladders was Ricky's favorite game. (Chutes and Ladders is a game—a single entity.)
  All the King's Men by Robert Penn Warren is a good book to read if you are interested in politics. (Though the book's title features a plural noun, men, the title is considered a single entity. Thus, the verb is should be used.)

Here are some more handy rules about compound subjects to know and use in your writing.

• Rule #3: When singular subjects are joined by or or nor, use a singular verb.
  Neither the kangaroo nor the ostrich was awake.
  Either the monkey or the giraffe is here.
• Rule #4: Plural subjects joined by or or nor agree in number with a plural verb.
  The girls or the boys are going to the playground.
  Neither the girls nor the boys are at the playground.
• Rule #5: When a singular subject and a plural subject are joined by or or nor, the verb agrees in number with the subject closer to it.
  Neither the assistants nor the police captain has called you.
  Either the police captain or her assistants have called you.
  Either he or his three friends are going to the library this evening.
Neither they nor she is here.
• Rule #6: If the compound subjects are in an interrogative sentence, answer the question to see which subject is closer to the verb.
  (Has, Have) either the boy or the girls reached the location? Answer the question: No, neither the boy nor the girls have reached the location.
  (Was, Were) either the girls or the boy with you at the dance? Answer the question: No, neither the girls nor the boy was with me at the dance.