Subject-Verb Agreement
Subject-verb agreement means matching a verb's form to whether its subject is singular or plural, and in most sentences this happens so automatically that it barely registers as a rule at all — the trouble starts precisely in the sentences where something sits between the subject and the verb, or where the subject's number isn't as obvious as it first looks, which is where even careful, experienced writers slip.
The basic pattern
A singular subject takes a singular verb, and a plural subject takes a plural verb: The dog barks. The dogs bark. This is trivially easy in short, simple sentences, and the difficulty only appears once real sentences complicate the space between subject and verb, or dress the subject up in ways that obscure its true number.
Prepositional phrases between subject and verb
A prepositional phrase inserted after the subject never changes the verb's agreement, no matter how it sounds: The basket of apples was on the table (not 'were,' because 'basket,' not 'apples,' is the true subject). One of the reasons is unclear (not 'are,' because 'one,' not 'reasons,' is the subject). This is the single most common source of agreement errors in real writing, because the noun sitting closest to the verb — 'apples,' 'reasons' — is not actually the noun the verb has to agree with, and proximity tricks the ear more reliably than it should.
Compound subjects joined by 'and'
Subjects joined by 'and' are almost always plural and take a plural verb: The manager and the intern were both late. The exception is when the two nouns form one single, unified idea treated as one entity: Macaroni and cheese is my favorite meal (one dish, singular verb) — the test is whether the compound subject is functioning as one conceptual unit or as two genuinely separate things.
Subjects joined by 'or' or 'nor'
When subjects are joined by or/nor/either...or/neither...nor, the verb agrees with whichever subject is closest to it, not with the whole compound: Neither the coach nor the players were happy with the call. Neither the players nor the coach was happy with the call. This proximity rule specifically for or/nor constructions is different from the and rule above, and it's worth memorizing as its own case rather than assuming or/nor behaves the same way and always shares one fixed plural/singular treatment.
Collective nouns
Collective nouns (team, committee, family, jury, staff) can take either a singular or plural verb depending on whether the group is being treated as one unit or as its individual members acting separately: The team is in first place (one unit, standings). The team are arguing among themselves (individual members, especially common in British English, where collective nouns take plural verbs more readily than in American English). This is a genuine, meaningful choice rather than an error either way — see the dedicated collective nouns guide for the fuller pattern across American versus British convention.
Indefinite pronouns
Pronouns like everyone, everybody, someone, anybody, nobody, and each are grammatically singular, even though 'everyone' feels intuitively like it refers to many people: Everyone is welcome to attend. Each of the applicants was interviewed separately. This mismatch between grammatical singularity and semantic plurality is one of the more persistently confusing agreement rules in English, and it also drives a related, separate debate over whether these pronouns can take 'they' as a singular pronoun later in the same sentence (a distinct but related agreement question covered in the pronoun-antecedent guide).
Inverted sentence order
When a sentence's normal subject-verb order is inverted — often after 'there' or 'here,' or in questions — it's easy to match the verb to the wrong word: There is a reason for this (not 'reasons,' since 'a reason' is the true subject, positioned after the verb). There are several reasons for this. Because the verb comes before the subject in these constructions, writers sometimes default to a habitual 'there's' regardless of what follows, producing the common informal error 'there's several reasons,' which formal writing treats as a genuine agreement mistake.
Titles, amounts, and other special singular cases
Titles of single works (books, films, albums) take a singular verb even if the title itself contains a plural noun: The Grapes of Wrath is a classic novel. Similarly, amounts of money, distance, and time are treated as single units rather than as a count of separate items: Ten dollars is not enough. Five years feels like a long time. In each case, the sentence is really talking about one thing — one book, one sum, one span of time — even though the surface wording contains a plural-looking noun, which is exactly why the singular verb is correct despite looking mismatched at first glance.
Agreement with 'each,' 'every,' and similar quantifiers before compound subjects
Even when 'each' or 'every' precedes what looks like a compound subject joined by 'and,' the verb stays singular, because each/every forces the sentence to consider its items one at a time rather than as a group: Each boy and girl was given a gift (not 'were,' since 'each' distributes the action individually across the list rather than treating 'boy and girl' as one combined plural subject). This is a distinct exception from the ordinary 'and creates a plural subject' rule covered earlier, triggered specifically by the presence of each or every at the front of the phrase.
Agreement with fractions and percentages
Fractions and percentages take their verb form from the noun that follows 'of': Half of the cake was eaten (singular cake). Half of the cookies were eaten (plural cookies). Fifty percent of the respondents agree (plural respondents). This pattern differs from most other subject-verb rules because the fraction or percentage phrase itself doesn't fix the number — it defers entirely to whatever noun comes after 'of,' which is worth remembering since it looks superficially similar to the collective-noun and indefinite-pronoun patterns covered above but actually works by a different logic.
Long, interrupted subjects with relative clauses
When a relative clause (starting with who, which, or that) sits between the subject and the verb, the same core principle applies as with simple prepositional-phrase interruptions: find the true head noun and ignore everything the relative clause adds. The list of restrictions that the committee proposed was rejected (the true subject is 'list,' not 'restrictions' or 'committee,' both of which sit closer to the verb but aren't what the sentence is actually about).
Why this rule causes so much trouble in long, formal sentences
Subject-verb agreement errors cluster disproportionately in long, formal, or bureaucratic writing — legal documents, academic prose, corporate reports — precisely because those genres favor long subjects loaded with modifying phrases and clauses, giving the reader's (and writer's) ear more opportunity to latch onto the wrong nearby noun instead of the true subject. Shorter, more conversational sentences rarely trigger this error simply because there's less distance, and fewer intervening nouns, between subject and verb for the mismatch to hide in.
A systematic method for checking agreement in a finished draft
When proofreading a document specifically for agreement, it helps to isolate each sentence's main verb, trace backward to find its true grammatical subject while mentally bracketing out every prepositional phrase, relative clause, and parenthetical aside along the way, and then check the match in isolation, ignoring everything else in the sentence. This deliberate, mechanical process catches errors that simply reading the sentence at normal speed tends to miss, since fluent reading naturally glosses over exactly the kind of noun-proximity traps that cause most real agreement mistakes.
Frequently asked questions
Is 'the data is' or 'the data are' correct?
Both appear in edited writing. Historically 'data' is the plural of the Latin 'datum' and strict style guides prefer 'data are'; in everyday and much scientific usage today, 'data' functions as a mass noun and 'data is' is now widely accepted, particularly in less formal or general-audience writing.
Does 'none' always take a singular verb?
No — this is a common myth. 'None' can take either a singular or plural verb depending on whether it means 'not one' (singular) or 'not any' referring to a plural group (plural): None of the cake was eaten. None of the guests were late. Most modern usage guides reject the idea that 'none' must always be singular.
How do I fix agreement errors caused by long, complex subjects?
Mentally strip out every modifying phrase and clause until only the bare subject noun remains, then match the verb to that noun alone. This isolates the true subject from any intervening prepositional phrases, appositives, or clauses that might otherwise mislead the ear.
Does 'the number of' take a singular or plural verb?
'The number of' is treated as singular (The number of applicants was surprising), while 'a number of' is treated as plural (A number of applicants were interviewed) — a subtle distinction that hinges on which word, 'the' or 'a,' precedes 'number,' since each phrase is conventionally treated as its own fixed idiom with its own agreement pattern. Careful editors watch for this pair specifically because it's easy to conflate the two phrases.