The Easy Guide to English Subject-Verb Agreement
Verbs and their subjects must "agree." We often call this "subject-verb agreement."
What is subject-verb agreement?
to agree: when two or more parties (people or groups) have the same opinion
"Agreement" in grammar occurs when a word must be in a particular form to relate correctly to the words around it.
In Standard English, verbs in any tense and their subjects must agree in two ways: in person and in number.
Person: "I" is a subject pronoun and first person singular. "We" is a subject pronoun and first person plural.
"Am" is always singular verb with first person (I).
"Are" can be and is usually used as a plural verb.
Those seem easy enough, but what about the trickier cases? Here we go.
Proper nouns (names) can be plural (end in s --or i in Latin) but refer to only one person, place, or thing. Don’t worry! The reasons are easy to understand.
Here are some examples:
Mumps is a common childhood disease.
Why? Mumps looks like it is plural, but "mumps" is really the name of a single disease, so it is a singular noun despite the “s” on the end.
There are some other names that are plural (ending with “s”) but which require singular verbs.
The United Nations is in New York City.
Where is The United Nations? It is in New York City.
Why? The United Nations (capitalized) is a single organization rather than multiple nations, so it is treated as a singular noun:
Here is a different usage of these same words “the united nations" when the words are not capitalized:
The united nations of Canada, the United States, and Mexico were able to defeat the mumps through a vaccine program.
Same meaning: When united, the nations of Canada, the United States, and Mexico were able to defeat the mumps through a vaccine program.
Why? Here we are referring to multiple nations which were united, not the name of an organization.
Whether indefinite pronouns--and other determiners--are singular, plural, or can be used for both is usually obvious, but these can also be tricky sometimes.