Subject-verb agreement

Intuition [Beginner]

Subject-verb agreement means the verb in a sentence must match the subject in number. If the subject is singular (one thing), the verb takes a singular form. If the subject is plural (more than one), the verb takes a plural form.

In English, agreement shows up most clearly in the present tense with third-person subjects:

Subject	Verb form	Example
He / She / It (singular)	verb + -s	She runs.
They / We / You (plural)	base verb	They run.

The key rule: a singular subject takes -s on the verb; a plural subject does not.

Visual [Beginner]

SINGULAR subject  --> verb + -s
  "The dog  chases  the ball."
       |       |
    singular  singular verb

PLURAL subject    --> base verb (no -s)
  "The dogs chase  the ball."
       |      |
    plural   plural verb

Worked example [Beginner]

Apply agreement rules to fix each sentence.

1. "The students in the lab conducts experiments."

• Subject: The students in the lab -- head noun is students (plural).
• Verb should be plural: conduct.
• Corrected: "The students in the lab conduct experiments."

2. "Each of the letters were delivered on time."

• Subject: Each (singular indefinite pronoun).
• Verb should be singular: was.
• Corrected: "Each of the letters was delivered on time."

3. "The committee are meeting tomorrow."

• Committee is a collective noun. In American English it is treated as singular.
• Corrected (American): "The committee is meeting tomorrow."

Check your understanding [Beginner]

Formal definition [Intermediate+]

Subject-verb agreement in English is a syntactic dependency in which the finite verb inflects to match the person and number features of the subject NP. In practice, the overt morphological reflex in modern English is limited:

• Third-person singular present: verb + -s (e.g., walks, has, is)
• Third-person plural present: base form (e.g., walk, have, are)
• Past tense of be: was (singular) vs. were (plural)
• All other past tense verbs: no agreement distinction (walked is used for all persons and numbers)

The subject is structurally defined as the NP in the specifier of the tense phrase (TP) or, in traditional terms, the NP that the sentence is about.

Key concepts [Intermediate+]

1. Intervening phrases. A prepositional phrase or other modifier between the subject and the verb does not change agreement. "The [list of items] is long" -- the verb agrees with list, not items.

2. Indefinite pronouns. Words like each, every, everyone, nobody, either, neither are grammatically singular despite conceptual plurality. "Everyone has finished" (not have).

3. Collective nouns. Nouns like committee, team, family, audience denote a group. In American English they are typically singular ("The team is ready"). In British English plural agreement is common ("The team are ready").

4. Proximity agreement (nearest-subject rule). With disjunctive coordinators (or, nor), the verb agrees with the closest subject: "Neither the dogs nor the cat is here" vs. "Neither the cat nor the dogs are here."

5. Inverted sentences. When the verb precedes the subject, agreement still applies to the postverbal NP: "There are three options" (not is), because the notional subject three options is plural.

Linguistic theory [Master]

Agreement is a core phenomenon in morphosyntax and has been central to theories of the syntax-morphology interface. In Government and Binding theory (Chomsky 1981), agreement is mediated by the AGR node (later split into AGR-S and AGR-O), a functional head in the inflectional layer that carries person and number features and establishes a Spec-head relation with the subject.

In the Minimalist Program, the AGR node was eliminated (Chomsky 1995). Agreement is instead captured by the operation Agree, which establishes a feature-matching relation between a probe (typically T) and a goal (the subject NP) without requiring movement. The probe searches its c-command domain for an active goal with matching interpretable features, and uninterpretable features are valued and subsequently deleted at the interfaces.

Corbett (2006) in his typological work distinguishes syntactic agreement (mechanical, feature-driven) from semantic agreement (based on meaning). English collective nouns illustrate the tension: "The committee is unanimous" (syntactic: singular) vs. "The committee are arguing among themselves" (semantic: notionally plural). Corbett's Agreement Hierarchy predicts that semantic agreement is more likely in attributive > predicative > relative pronoun > personal pronoun positions.

Notional vs. formal agreement has a long history. Traditional grammar emphasizes formal (grammatical) features, while functionalist approaches (Halliday 1994) treat agreement as a realization of the interpersonal metafunction -- the speaker's construal of the subject's referential status.

Historical context [Master]

Old English had far richer agreement morphology than Modern English. Verbs agreed with their subjects in both person (1st, 2nd, 3rd) and number (singular, plural) across all tenses, and adjectives agreed with nouns in case, gender, and number. The progressive erosion of inflectional endings from Middle English onward (driven by language contact after the Norman Conquest, phonological reduction of unstressed syllables, and the loss of grammatical gender) left Modern English with the minimal agreement system we see today: essentially just the third-person singular -s in the present tense and the was/were distinction.

The third-person singular -s itself has an interesting history. In early Middle English, the dominant suffix in the south was -eth (he goeth), while -s was a northern form influenced by Old Norse. Over the 15th-16th centuries, -s spread southward and displaced -eth in ordinary speech, a rare example of a northern dialect feature becoming the standard.

African American Vernacular English (AAVE) and some Southern American English varieties optionally allow zero-marking on third-person singular present verbs ("He walk to school"), a feature with roots in the contact linguistics of the early American South. Prescriptive grammar treats this as non-standard, but linguistically it represents a systematic reduction in agreement morphology parallel to what happened in the history of English more broadly.

Bibliography [Master]

• Chomsky, N. (1981). Lectures on Government and Binding. Foris.
• Chomsky, N. (1995). The Minimalist Program. MIT Press.
• Corbett, G. G. (2006). Agreement. Cambridge University Press.
• Halliday, M. A. K. (1994). An Introduction to Functional Grammar (2nd ed.). Arnold.
• Huddleston, R., & Pullum, G. K. (2002). The Cambridge Grammar of the English Language. Cambridge University Press.
• Lass, R. (1992). The shape of English: Structure and history. British Studies Series.
• Pullum, G. K. (1976). The Duke of York gambit. Journal of Linguistics, 12(1), 83-102.