Subject-Verb Agreement — Apply subject–verb agreement in simple and complex sentences

Historical Context & Motivation

The principle of subject–verb agreement — the requirement that a verb's form match the number and person of its subject — is one of the oldest and most persistent features of the English language. This grammatical rule descends from the elaborate inflectional system of Old English, a language in which verbs changed form not only for number (singular vs. plural) but also for person (first, second, third) across multiple tenses. As English evolved through centuries of contact with Norse, French, and Latin, it shed most of those inflections, yet the core demand for concord between subject and verb survived. Understanding this history illuminates why agreement errors feel so conspicuous to native speakers and why the ACCUPLACER ESL Language Use section tests this skill so directly: it is a fundamental marker of grammatical control.

The central question this lesson addresses is deceptively simple: How does a writer ensure that every verb in a sentence — whether in a simple independent clause or buried within a complex subordinate structure — correctly reflects the number of its true subject? Mastering this skill requires more than memorizing a rule; it demands the ability to parse sentence architecture, strip away intervening phrases, and apply agreement consistently across embedded clauses, inverted constructions, and tricky compound subjects.

Core Principles of Subject–Verb Agreement

Subject–verb agreement rests on a small set of foundational principles that, once internalized, govern every sentence you write or encounter on the ACCUPLACER. The overarching rule is that a singular subject takes a singular verb and a plural subject takes a plural verb. In present tense, this manifests as the third-person singular '-s' ending: 'she runs' (singular) vs. 'they run' (plural). The principles below capture the nuances that make real-world application challenging.

Visual Explanation — Mapping Subject to Verb

The diagram below illustrates how to trace the agreement path in a sentence that contains intervening modifiers. The key visual insight is that the verb must 'look past' all modifying phrases and connect directly to the head noun of the subject. This is the single most tested pattern on the ACCUPLACER ESL Language Use section.

As the diagram makes clear, the ACCUPLACER frequently tests sentences in which one or more prepositional phrases separate the subject from the verb. The plural noun nearest to the verb position can create a powerful attraction effect — a phenomenon linguists call agreement attraction — that leads writers to select a plural verb when a singular one is required. The remedy is systematic: (1) locate the verb, (2) ask 'who or what performs this action?', (3) confirm the number of that head noun, and (4) verify the verb form matches. This four-step parse becomes automatic with practice and is the procedural core of sections 4 and 6 below.

The Agreement Mechanism — How It Works

Unlike disciplines that rely on mathematical formulas, subject–verb agreement follows a logical decision procedure. You can think of this mechanism as a flowchart: each decision point narrows the options until only the correct verb form remains. Below, we formalize the decision rules that govern the most common ACCUPLACER patterns.

Rule 1: Standard Agreement

In present tense, a third-person singular subject (he, she, it, or any singular noun) requires the verb base + '-s' or '-es.' All other subjects (I, you, we, they, or any plural noun) take the base form without the '-s.' For the verb 'to be,' the forms expand: 'am' (first-person singular), 'is' (third-person singular), 'are' (plural and second-person), 'was' (past singular), 'were' (past plural). These irregular forms are among the most heavily tested items on the ACCUPLACER.

Rule 2: Intervening-Phrase Immunity

Words that appear between the subject and verb — prepositional phrases ('of the students'), participial phrases ('including the manager'), and parenthetical asides ('as well as her colleagues') — do not change the number of the subject. Note especially that phrases beginning with 'along with,' 'together with,' 'as well as,' 'in addition to' are not true conjunctions; they are prepositional or adverbial modifiers, so they do not create a compound subject. 'The professor, along with her assistants, is conducting the experiment' — singular, because 'professor' alone is the subject.

Rule 3: Compound-Subject Coordination

When two or more subjects are joined by 'and,' the compound subject is typically plural: 'The dean and the registrar have approved the policy.' The exception arises when the two nouns refer to a single entity or concept: 'Bread and butter is my favorite snack.' When 'or,' 'nor,' 'either…or,' or 'neither…nor' coordinate the subjects, the verb agrees with the subject closest to the verb — the so-called proximity rule.

Rule 4: Indefinite-Pronoun Categories

Rule 5: Collective Nouns and Special Subjects

Collective nouns like team, committee, family, audience, jury are singular when the group acts as a unit ('The committee has reached a decision') and plural when members act individually ('The committee have disagreed among themselves'). In American English, the singular usage predominates and is what the ACCUPLACER typically expects. Subjects that are titles, organization names, or quantities treated as a lump sum also take singular verbs: 'Twenty dollars is too much for that book'; 'The New York Times publishes daily.'

Agreement in Complex and Compound-Complex Sentences

The ACCUPLACER ESL Language Use section does not limit itself to simple, single-clause sentences. Many items embed the agreement challenge inside complex sentences (an independent clause plus one or more dependent clauses) or compound-complex sentences (multiple independent clauses plus at least one dependent clause). In these structures, each clause has its own subject–verb pair, and each pair must agree independently. The diagram below maps the clause architecture of a typical ACCUPLACER-style complex sentence.

Relative-Pronoun Agreement Strategy

One of the trickiest patterns in complex sentences involves the relative pronouns who, which, and that. These pronouns do not have inherent number — they borrow it from their antecedent, the noun they refer back to. Consider: 'She is one of the scientists who have published in that journal.' Here, 'who' refers to 'scientists' (plural), so 'have published' is correct. But compare: 'She is the only one of the scientists who has published in that journal.' Now 'who' refers to 'one' (singular, emphasized by 'the only'), so 'has published' is correct. This subtle shift is precisely the type of nuance the ACCUPLACER rewards careful readers for detecting.

Adverbial and Noun Clause Patterns

Complex sentences may also contain adverbial clauses introduced by subordinators like 'because,' 'although,' 'when,' or 'if.' Each adverbial clause has its own subject–verb pair: 'Although the results seem promising, the team needs more data.' Additionally, noun clauses functioning as subjects are always singular: 'What the researchers discovered was surprising.' The entire clause 'What the researchers discovered' functions as one singular subject.

Worked Example — ACCUPLACER-Style Item

Let us walk through a realistic ACCUPLACER ESL Language Use question. The task is to select the correct verb form for the blank in a complex sentence.

Options: (A) is (B) are (C) was (D) were

Common Errors and How to Avoid Them

Even advanced language learners encounter predictable pitfalls in subject–verb agreement. The following table catalogs the most common error types that appear on the ACCUPLACER, along with strategies for avoiding them.

Connection to Advanced Grammar & Beyond the ACCUPLACER

Mastering subject–verb agreement for the ACCUPLACER is not an end in itself — it is the foundation for more advanced grammatical competencies that college-level writing demands. The table below contrasts the agreement skills tested on the ACCUPLACER with the extended applications you will encounter in academic writing, standardized tests like the TOEFL iBT, and professional communication.

One advanced pattern worth previewing is the subjunctive mood, which overrides the normal agreement rule. In sentences expressing demands, recommendations, or necessity — often signaled by verbs like 'recommend,' 'insist,' 'require,' or adjectives like 'essential,' 'important' — the verb in the 'that' clause takes the bare infinitive form regardless of the subject's number. 'The board insists that the CEO resign immediately' — not 'resigns.' While this pattern rarely appears on the ACCUPLACER, awareness of it strengthens your overall grammatical framework and prepares you for college-level writing tasks.

Practice Problems

The following five problems mirror the style and difficulty progression of ACCUPLACER ESL Language Use items. For each, select the correct verb form and then read the full explanation to reinforce the underlying principle.

Lesson Summary