Subject–Verb Agreement

Making Verbs and Subjects Agree in Number

Illustration of subject verb agreement
Singular subject takes a singular verb, and a plural subject takes a plural verb.

Subject-Verb Agreement is a fancy term for an idea that seems simple enough: the subject and the verb must walk together—meaning a singular subject takes a singular verb, and a plural subject takes a plural verb.

But the problem is, not all subjects clearly proclaim themselves to be singular or plural, and in many cases the plain grammatical form of the subject conflicts with our sense of the intended meaning. For this reason grammarians have introduced the mechanism of s–endings, used in determining the condition of the subject and thus supplying the appropriate verb.

To adhere to the rules of subject-verb agreement, you must understand the concept of s–endings; for the rules guiding subject-verb agreement are all based on the use of S-endings.

There must be agreement between subject and verb in a sentence:

singular subjects should be used with singular verbs:
  • The pen writes.
    [Correct! subject is singular, verb also is singular]
likewise, plural subjects should be used with plural verbs:
  • The pens write.
    [Correct! subject is plural, verb also is plural]
Important Hint!  

You must note and not get confused between singular and plural verbs, because not all words ending in –s are plural. The –s has several other uses, depending on the kind of word it’s being tagged to. In the examples above, many learners might think ‘writes’ as a plural verb and ‘write’ as a singular verb.

Plural verbs forms are just opposite in the way nouns take their plural forms. Nouns are naturally made plural by adding ‘–s’ or ‘–es’ in singular noun. On the other hand, if you add ‘–s’ or ‘–es’ in a verb it becomes singular. As it is in the following:

Noun + s/es = PluralVerb + s/es = Singular
Singular Nounball, bench, book, utensilSingular Verb kicks, runs, sings, wanders
Plural Nounsballs, benches, books, utensilsPlural Verbskick, run, sing, wander

Types of S–Endings

A.  The Natural S Several words in English have an S as their final letter. Meanwhile, these S’s are not endings. They only make part of the basic spelling of the word. For example, kiss, bus, miss, Paris, etc., all end in s the way other words may end in t or n or r, etc.

B.  The Noun S This is the common Plural S. By adding an S to the end of a singular noun, the noun becomes plural:

SingularPlural (+s)

By adding an –s ending, we now increase our object from one to more than one.

Sometimes a noun already ends in a Natural S. In such a case, we add an –es ending to make it plural, as follows:

SingularPlural (+es)

Other Uses of –es

An –es is used if a noun ends in ch, sh, x, or z:

SingularPlural (+es)

Likewise, nouns that ends in letter –y form plurals in one of two ways:

1.   If the letter before the –y is a consonant, the plural is formed by changing –y to I, then adding –es:

SingularPlural (–y + ies)

2.   When the letter before the –y is a vowel; an s is added.

SingularPlural (+s)

Note also that some nouns ending with letter fe or fe become plural by altering the f to v before adding –es:

SingularPlural (f › v + es)

However, some become plural by addition of an –s:

SingularPlural (+ s)

There are also nouns with an –o ending. These group of nouns form their plural by adding an –s:

SingularPlural (+ s)

Similarly, other nouns that end in –o take an –es to become plural:

SingularPlural (+ es)

C.  The Possessive S (’s or s’) — This form of S– ending is typically attached to nouns. But it does not pluralise a singular noun. However, the Possessive S converts a noun into a kind of adjective:

Let's observe the following sentences:
  • John has a bicycle.
  • John’s bicycle is blue. (the bicycle of John is blue.)

In the first sentence, the verb is has, the subject is John. Therefore, John is used as a noun.

In the second sentence, however, the verb is is, and the subject is bicycle. The word John’s is describing the word bicycle. This simply means that by adding the ’s, we converted an ordinary noun into an adjective.

By virtue of these demonstrations (we have observed), the difference between the Noun S and the Possessive S is the use of a punctuation mark, which is known as an apostropheOpens in new window.

Important Hint!  

Note that to make a plural noun possessive, we do not necessarily add ’s. We simply add an apostrophe (’), as the S is already there. (The boys’ bicycles are blue [The bicycles of the boys are blue.])

D.  The Verb S The Verb S–ending is a rather tricky one. It is reverse of the way we generally think of s–endings. First and foremost, it is added to Verbs, not nouns. Secondly, it makes a verb becomes singular.

The basic rule is, when the subject of a present tense verbOpens in new window is a singular noun, the verb takes an S–ending:
Examples include:
  • The pianist plays pianos.
  • The doctor treats patients.
If the present tense verb has a plural noun for a Subject, the verb gets No S–ending:
Examples include:
  • The pianists play pianos.
  • The doctors treat patients.

Note that this means that between a verb and its subject there is just only one S–ending to go around. Either there is an S on the verb, or there is an S on the subject.

Examples include:
  • Her honeymoon seems extravagant.
  • Their honeymoons seem extravagant.

On the other hand, if a singular noun ends with a Natural S, it has no S–ending. So its verb would still need to be tagged with an S–ending:

Examples include:
  • The boss cajoles his employees.
  • The bosses cajole their employees.