Recognize and correct subject–verb agreement errors - Health Education Systems Admission Assessment HESI

SECTION 1

Historical Context & Motivation

The principle of subject–verb agreement is among the oldest and most enduring rules of English grammar, rooted in the inflectional morphology inherited from Old English and, before that, Proto-Germanic. In highly inflected languages, verbs shift form to match the person, number, and sometimes gender of their subjects—a phenomenon called concord. Although Modern English has shed most of its inflectional endings, the requirement that a singular subject take a singular verb and a plural subject take a plural verb persists as a cornerstone of standard written English. For graduate-level examinees preparing for the HESI A2, this rule is not merely academic; it surfaces repeatedly in clinical documentation, research reporting, and professional communication, where a single agreement error can introduce ambiguity into patient care directives or data analysis.

c. 450–1100 • Old English Concord

Old English verbs carried distinct endings for first, second, and third persons in both singular and plural, making agreement errors nearly impossible to overlook. The verb 'singan' (to sing) conjugated as 'ic singe,' 'þū singest,' 'hē singeþ,' etc.

c. 1100–1500 • Middle English Leveling

Inflectional endings eroded through vowel reduction and dialect mixing after the Norman Conquest. The third-person singular '-eth' ending and the plural '-en' ending began to collapse, creating ambiguity that made agreement rules increasingly dependent on word order and proximity.

1762 • Lowth's Prescriptive Grammar

Robert Lowth published 'A Short Introduction to English Grammar,' codifying subject–verb agreement rules that remain influential. His prescriptive approach established the formal guidelines tested on standardized examinations today.

1996–Present • HESI A2 and Standardized Testing

The HESI A2 exam, developed by Elsevier, incorporates grammar sections that assess subject–verb agreement as a measure of the communication competence required in healthcare settings, where grammatical precision directly affects patient safety.

The central question this lesson addresses is deceptively straightforward: how does a writer consistently identify the true subject of a sentence—stripping away intervening phrases, inverted syntax, and compound structures—and then select the verb form that agrees with it in number? The challenge lies not in the rule itself but in the numerous syntactic constructions that obscure the relationship between subject and verb, particularly in the complex, information-dense sentences characteristic of scientific and clinical writing.

SECTION 2

Core Principles of Subject–Verb Agreement

At its most fundamental level, subject–verb agreement requires that a singular subject pairs with a singular verb and a plural subject pairs with a plural verb. In English, this distinction is most visible in the present tense, where the third-person singular verb typically takes an '-s' or '-es' suffix ("she runs"), while the plural form does not ("they run"). Although the rule appears simple, its application demands an ability to parse sentence architecture and identify the grammatical subject amidst modifying phrases, appositives, and clausal embeddings.

Identify the True Subject

The grammatical subject governs agreement, not nouns in intervening prepositional phrases. In 'The collection of rare specimens was impressive,' the subject is 'collection' (singular), not 'specimens.'

Compound Subjects & Conjunctions

Subjects joined by 'and' are generally plural ('The nurse and the physician collaborate'). Subjects joined by 'or' or 'nor' agree with the nearer subject ('Neither the residents nor the attending was available').

Indefinite Pronouns

Pronouns such as 'each,' 'everyone,' 'nobody,' and 'either' are always singular. Others—'few,' 'many,' 'several'—are always plural. Some ('all,' 'some,' 'none') depend on the noun they refer to.

Inverted Sentence Order

In sentences beginning with 'there' or 'here,' the subject follows the verb. 'There are multiple contraindications' is correct because 'contraindications' (plural) is the true subject.

Collective Nouns

Words like 'team,' 'staff,' and 'committee' are singular when acting as a unit ('The staff meets daily') but plural when members act individually ('The staff disagree about the protocol').

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KEY TAKEAWAY

Think of subject–verb agreement like a lock and key in pharmacology: just as the correct ligand must match the receptor's binding site for a physiological response, the verb must match the subject's number for the sentence to function correctly. Intervening phrases are like allosteric modulators—they sit near the active site but do not change which key fits the lock. Always return to the true subject (the receptor) to determine which verb form (the ligand) produces grammatical concord.

SECTION 3

Visual Explanation: Parsing the Subject–Verb Relationship

The diagram illustrates how the true subject ("results") governs verb agreement, while the intervening prepositional phrase ("of the clinical trial") must be mentally bracketed. The agreement link shows the direct connection between subject and verb, bypassing the distractor noun.

The visual above encapsulates the most common source of subject–verb agreement errors on the HESI A2: the proximity trap. When a prepositional phrase, appositive, or relative clause intervenes between the subject and the verb, writers tend to match the verb to the nearest noun rather than to the grammatical subject. The solution is systematic: mentally strip away all modifying phrases, locate the simple subject, determine its number, and then select the verb form that agrees. This parsing strategy—illustrated by the bracketed prepositional phrase in the diagram—becomes second nature with deliberate practice and is especially critical when reading and correcting sentences on a timed exam.

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How Subject–Verb Agreement Works: Rules & Patterns

Rule 1: Prepositional Phrases Do Not Affect Agreement

A prepositional phrase beginning with words such as "of," "in," "with," "along with," "together with," "as well as," or "in addition to" never changes the number of the subject. The phrase "along with her colleagues" in the sentence "The researcher, along with her colleagues, presents the findings" is parenthetical; the subject is still "researcher" (singular), so the verb takes the singular form. This rule is particularly relevant in clinical and research contexts where authors frequently embed qualifying phrases between subjects and verbs.

Rule 2: Compound Subjects

When two or more subjects are joined by "and," the compound subject is plural: "Medication adherence and patient education are essential." The exception arises when two nouns refer to a single entity or concept: "Macaroni and cheese is a comfort food." When subjects are joined by "or," "nor," "either...or," or "neither...nor," the verb agrees with the subject nearest to it: "Neither the attending physician nor the residents were available."

Rule 3: Indefinite Pronouns

Always Singular	Always Plural	Depends on Context
each, every, everyone, everybody, everything	both, few, many, several	all, any, more, most, none, some
anyone, anybody, anything	others	Agree with the noun in the "of" phrase: "Some of the data is…" vs. "Some of the patients are…"
either, neither, one, no one, nobody, nothing

Indefinite Pronoun Agreement Reference

Rule 4: Inverted Sentences & Expletive Constructions

In sentences beginning with "there" or "here," the subject follows the verb. These words are expletives (grammatical placeholders) and never function as subjects. To determine agreement, mentally rearrange the sentence: "There are several contraindications" becomes "Several contraindications are there." The plural subject "contraindications" demands the plural verb "are." Similarly, questions often invert subject and verb: "Does the patient exhibit symptoms?" correctly uses the singular auxiliary "does" with the singular subject "patient."

Rule 5: Collective Nouns & Special Cases

Collective nouns—"committee," "team," "staff," "group," "family"—are singular when the group acts as one unit and plural when individual members act separately. In American English, the singular interpretation predominates: "The committee has decided on a new protocol." Nouns that are plural in form but singular in meaning—such as "news," "mathematics," "measles," and "physics"—take singular verbs. Conversely, nouns like "scissors," "trousers," and "proceeds" are always plural: "The proceeds were donated to the clinic."

SECTION 5

Tricky Cases & Common HESI A2 Patterns

This decision flowchart guides you through the systematic process of selecting the correct verb form. Begin by eliminating intervening phrases, identify the simple subject, determine its number, and apply the appropriate special rule if needed.

Relative Clauses

When a relative pronoun ("who," "which," "that") serves as the subject of a clause, the verb agrees with the pronoun's antecedent. Consider: "She is one of those nurses who go above and beyond." Here, "who" refers to "nurses" (plural), so the verb is plural. However, "She is the only one of the nurses who goes above and beyond" uses a singular verb because "the only one" narrows the antecedent to a single individual. This distinction is a frequent source of error on standardized exams and demands careful attention to meaning.

Titles, Measurements, and Amounts

Titles of works, names of organizations, and words referred to as words are always singular: "'Fundamentals of Nursing' is required reading." Amounts and measurements treated as a single unit are also singular: "Five milligrams is the standard dosage" and "Three hours is sufficient for the infusion." This convention appears regularly in clinical documentation and is tested on the HESI A2.

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HESI A2 TIP

On the HESI A2, agreement questions often embed the error in a complex sentence with multiple modifiers. Read the answer choices aloud when possible: incorrect agreement frequently "sounds wrong" even when the syntactic structure is complex. If you can quickly identify the simple subject and match it to the verb, you can eliminate distractors with confidence.

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Worked Example: Correcting Agreement Errors

The following worked example mirrors the format and complexity of HESI A2 grammar items. We will walk through a multi-step correction process that applies several of the rules covered in previous sections.

Identifying and Correcting the Error

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Step 1 — Read the Original Sentence

Consider the following sentence: "Each of the patients who were admitted to the ICU require continuous cardiac monitoring." Your task is to determine whether the underlined verb is correct.
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Step 2 — Eliminate Intervening Phrases

Cross out the prepositional phrase "of the patients" and the relative clause "who were admitted to the ICU." The stripped sentence reads: "Each … require continuous cardiac monitoring."
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Step 3 — Identify the Simple Subject

The simple subject is "Each." Consulting the indefinite pronoun chart, "each" is always singular.

Subject: "Each" → Singular
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Step 4 — Check the Verb

The current verb is "require" (plural form). A singular subject demands the singular verb "requires." Note that "patients" (plural) and "were" (plural, correctly agreeing with "who" → "patients" in the relative clause) may have created a proximity trap, tempting the writer to use a plural main verb.
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Step 5 — Write the Corrected Sentence

The corrected sentence reads: "Each of the patients who were admitted to the ICU requires continuous cardiac monitoring." Note that "who were admitted" remains correct because "who" refers to "patients" (plural).

Corrected verb: requires (singular, agreeing with "each")

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Common Pitfalls vs. Effective Strategies

Common Pitfall	Example of Error	Effective Strategy
Proximity attraction	"The efficacy of the treatments were proven." (verb agrees with "treatments" instead of "efficacy")	Cross out all prepositional phrases; match verb to the remaining noun.
Indefinite pronoun confusion	"Everyone in the clinical rotations have completed the module." ("everyone" is singular)	Memorize the singular/plural/variable indefinite pronoun categories.
Inverted-order oversight	"There is several risk factors to consider." ("risk factors" is plural)	Rearrange "there is/are" sentences to place the subject first.
Collective noun ambiguity	"The nursing staff are meeting at 3 PM." (in American English, "staff" as a unit is singular)	Determine whether the group acts as one unit or as individuals; prefer singular in formal American English.
Or/nor agreement error	"Neither the surgeon nor the nurses was prepared." (verb should agree with nearer subject "nurses")	With or/nor, always match the verb to the subject closest to it.

Common Subject–Verb Agreement Pitfalls and Corrective Strategies

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KEY TAKEAWAY

Agreement errors often function like signal noise in a diagnostic instrument: the underlying data (the true subject) is clear, but extraneous input (intervening phrases, inverted syntax) distorts the output (the verb form). Just as a clinician calibrates equipment to filter noise and read the true signal, a skilled writer learns to filter syntactic distractors and match the verb to the actual grammatical subject. Developing this calibration requires memorizing the categories of tricky subjects—indefinite pronouns, collective nouns, correlative conjunctions—and practicing the "strip-down" technique consistently.

SECTION 8

Beyond Basic Agreement: Advanced Nuances

While the HESI A2 primarily tests standard agreement rules, understanding the broader landscape of agreement phenomena strengthens your ability to analyze complex sentences and prepares you for the kind of academic and clinical writing required in graduate programs. The table below contrasts the standard rules tested on the HESI A2 with more advanced considerations encountered in research writing and graduate-level prose.

Standard HESI A2 Rule	Advanced / Graduate-Level Nuance
Collective nouns are singular when acting as a unit.	In British English and some medical journals, collective nouns routinely take plural verbs ("The WHO have recommended..."). Know your target style guide.
"None" can be singular or plural depending on the referent.	Historically, "none" was treated as strictly singular ("not one"). Modern usage and the APA Publication Manual accept plural when referring to a countable set: "None of the participants were excluded."
"Data" is treated as either singular or plural.	In scientific writing, "data" is increasingly accepted as a mass noun (singular: "The data suggests..."), but many style guides in health sciences still require the traditional plural: "The data indicate..." Check institutional requirements.
The subject of a gerund phrase is the gerund itself (singular).	Complex nominal clauses ("What the researchers discovered was/were multiple anomalies") create notional agreement tensions. Formal grammar uses singular; notional grammar may use plural when the predicate nominative is plural.
Amounts and measurements are singular when expressing a total.	When the individual components are emphasized, plural is appropriate: "Two hundred milligrams were administered in separate doses" (emphasizing discrete administrations).

Standard vs. Advanced Agreement Considerations

As you advance into graduate coursework, you will encounter style-guide-specific conventions that may appear to contradict the prescriptive rules tested on standardized exams. The key is to internalize the standard rules first—these are what the HESI A2 tests—and then layer on discipline-specific conventions as required by your program's style manual, whether APA, AMA, or a particular journal's guidelines. Mastering the foundational rules equips you to recognize when a deviation is intentional and contextually appropriate versus when it constitutes a genuine error.

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Practice Problems

Question 1: CONCEPTUAL

Explain why the sentence "The list of medications need to be updated" contains an agreement error. What is the true subject, and what verb form should be used?

Show answer

The error arises because the writer has matched the verb "need" to "medications," the object of the preposition "of," rather than to the actual subject "list," which is singular. The prepositional phrase "of medications" modifies "list" but does not determine the verb's number. The corrected sentence should read: "The list of medications needs to be updated." This is a classic proximity trap: the plural noun nearest to the verb exerts a false gravitational pull on verb selection.

Question 2: BASIC

Select the correct verb form: "Neither the physician nor the nurses (was / were) aware of the allergy."

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The correct form is "were." When subjects are joined by "neither...nor," the verb agrees with the subject nearest to it. In this case, "nurses" (plural) is nearer to the verb, so the plural form "were" is required. If the sentence were reversed—"Neither the nurses nor the physician"—the correct verb would be "was," because "physician" (singular) would then be the nearer subject. This rule applies equally to "either...or" constructions.

Question 3: INTERMEDIATE

Identify and correct the agreement error(s) in the following sentence: "There is several contraindications, and each of the side effects are documented in the chart."

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This sentence contains two agreement errors. First, "There is several contraindications" should be "There are several contraindications" because the true subject "contraindications" is plural—"there" is an expletive, not the subject. Second, "each of the side effects are documented" should be "each of the side effects is documented" because "each" is an always-singular indefinite pronoun. The corrected sentence: "There are several contraindications, and each of the side effects is documented in the chart."

Question 4: APPLIED

A nursing student writes in a patient care report: "The team of surgeons, along with the anesthesiologist, have decided to postpone the procedure, and five milliliters of the solution were administered as a precaution." Identify all agreement errors and provide the corrected version with explanations.

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There are two errors. First, the subject of the main clause is "team" (singular collective noun), not "surgeons" or "anesthesiologist." The phrase "of surgeons" is a prepositional phrase, and "along with the anesthesiologist" is a parenthetical addition—neither changes the subject's number. The verb should be "has decided." Second, "five milliliters" refers to a single dosage (a unified amount), so it takes a singular verb: "was administered." The corrected sentence: "The team of surgeons, along with the anesthesiologist, has decided to postpone the procedure, and five milliliters of the solution was administered as a precaution."

Question 5: CRITICAL THINKING

Consider the sentence: "The data collected from the multicenter trial suggest that none of the experimental treatments were effective, but the committee has yet to publish its findings." A colleague argues that "suggest" should be "suggests" and "were" should be "was." Evaluate each claim, citing the applicable agreement rules and any style-guide considerations.

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The colleague's first claim concerns "data." In traditional and many scientific style guides (including AMA style), "data" is the plural of "datum," making "suggest" correct as a plural verb. However, some modern guides (including some APA contexts) accept "data" as a mass noun with a singular verb. On the HESI A2, both usages may appear; the key is internal consistency. The colleague's second claim concerns "none." When "none" refers to a countable noun ("none of the treatments"), it can take either singular or plural depending on emphasis. "None were effective" emphasizes each individual treatment and is widely accepted in standard usage. "None was effective" treats "none" as "not one" and is more formal. Both are defensible. The final clause, "the committee has yet to publish its findings," is unambiguously correct: "committee" is a collective noun acting as a unit (singular), and "its" correctly reflects that singular referent. In summary, the original sentence is grammatically sound under standard modern usage. The colleague's objections reflect prescriptive traditions that, while not incorrect, are not the only acceptable interpretation—a distinction graduate-level writers must navigate depending on the applicable style guide.

SUMMARY

Lesson Summary

Summary

Subject–verb agreement requires that every verb match its grammatical subject in number, regardless of intervening prepositional phrases, appositives, or relative clauses that may separate them. Compound subjects joined by "and" are plural, while those joined by "or" or "nor" agree with the nearer subject. Indefinite pronouns fall into three categories—always singular ("each," "everyone"), always plural ("few," "many"), and variable ("all," "some," "none")—and must be memorized. In inverted sentences beginning with "there" or "here," the true subject follows the verb and must be identified before agreement can be determined.

The systematic strategy for HESI A2 success is to strip away modifying phrases, locate the simple subject, determine its number, and match the verb accordingly. Collective nouns are singular when the group acts as a unit, and amounts and measurements functioning as a single quantity take singular verbs. Mastering these rules not only prepares you for the exam but also ensures precision in the clinical and academic writing that defines graduate-level healthcare communication.