Choose the best revision for clarity and correctness in a sentence - Health Education Systems Admission Assessment HESI

SECTION 1

Historical Context & Motivation

The capacity to identify the clearest, most correct version of a sentence is not merely an academic exercise—it reflects a centuries-long tradition of rhetorical precision that has shaped professional communication in medicine, law, and the sciences. The HESI A2 Grammar section tests this skill directly because healthcare professionals must compose and interpret clinical documentation where a single ambiguous modifier or a misplaced comma can alter a patient's treatment plan. Understanding the historical evolution of English grammar standards illuminates why certain constructions are preferred and how the conventions tested on the HESI A2 came to be codified.

1762 • Lowth's Prescriptive Grammar

Robert Lowth published A Short Introduction to English Grammar, establishing prescriptive rules for subject-verb agreement, pronoun case, and sentence structure that remain foundational in standardized testing.

1918 • Strunk's Elements of Style

William Strunk Jr. codified principles of clarity—omit needless words, use the active voice, place modifiers carefully—that became the gold standard for concise academic and professional prose.

1946 • Orwell's "Politics and the English Language"

George Orwell argued that vague or inflated language leads to imprecise thinking. His essay reinforced the principle that clarity in writing is an ethical obligation, especially in fields where lives depend on accurate communication.

2001 • HESI A2 Exam Introduced

Health Education Systems Inc. launched the HESI A2 as an admissions assessment for nursing and allied health programs, embedding grammar proficiency as a core competency alongside anatomy, math, and reading comprehension.

The central question the HESI A2 grammar section poses is deceptively straightforward: Which revision of this sentence is the clearest and most correct? Answering it requires you to synthesize knowledge of grammatical rules—subject-verb agreement, parallelism, pronoun reference, modifier placement—with a rhetorical sense of what makes prose unambiguous and efficient. This lesson equips you with a systematic framework for making that judgment under timed conditions.

SECTION 2

Core Principles of Clarity and Correctness

Choosing the best revision demands simultaneous attention to two distinct but interrelated dimensions: grammatical correctness (conformity with Standard Written English conventions) and rhetorical clarity (the ease with which a reader can extract the intended meaning). A sentence can be grammatically correct yet confusing, or it can be perfectly clear yet violate a rule of Standard Written English. The best revision satisfies both criteria simultaneously.

Subject-Verb Agreement

The verb must agree in number with its grammatical subject, not with intervening nouns in prepositional phrases or relative clauses. Errors often hide in sentences with compound subjects or collective nouns.

Modifier Placement

Adjectives, adverbs, and participial phrases must be positioned adjacent to the word or phrase they modify. Misplaced or dangling modifiers create ambiguity that can distort clinical meaning.

Parallel Structure

Items in a series, elements joined by coordinating or correlative conjunctions, and compared items must share the same grammatical form—all infinitives, all gerunds, or all noun phrases.

Pronoun Clarity & Agreement

Every pronoun must have a clear, unambiguous antecedent and must agree with that antecedent in number and person. Vague pronoun references are among the most common sources of unclear writing.

Conciseness & Active Voice

The best revision uses the fewest words necessary to convey complete meaning. Active voice is generally preferred because it clarifies who is performing the action, though passive voice is acceptable when the agent is unknown or irrelevant.

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KEY TAKEAWAY

Think of sentence revision like a differential diagnosis in clinical practice. Just as a clinician rules out competing diagnoses by systematically checking symptoms against criteria, you should evaluate each answer choice by checking it against the five core principles—agreement, modifiers, parallelism, pronoun clarity, and conciseness. The best revision is the one that passes every test, not merely the one that fixes the most obvious error.

SECTION 3

Visual Explanation: The Revision Decision Tree

The following decision-tree diagram illustrates the systematic process for evaluating candidate revisions. Begin at the top by reading the original sentence to identify the error type, then move through each checkpoint in sequence. A revision must clear every gate to qualify as the best answer.

The decision tree shows six sequential checkpoints. At each gate, eliminate any answer choice that introduces a new error or fails the criterion. The revision that passes all six gates is the best answer.

Notice that the tree is sequential but not hierarchical in importance—each checkpoint carries equal weight. A revision that fixes a subject-verb agreement error but introduces a dangling modifier is no better than the original. The HESI A2 frequently includes distractor answer choices that resolve one problem while creating another, so you must trace each candidate through every gate before selecting your answer.

SECTION 4

How the Error-Identification Mechanism Works

Because grammar is a rule-governed system rather than a mathematical one, the analytical framework for revision questions is best understood through a classification of error types and corresponding correction strategies. Each error type maps to a specific structural feature of the sentence, and the correction strategy specifies what transformation produces a grammatically correct and rhetorically clear result.

Error Type 1: Subject-Verb Disagreement

The most frequently tested error on the HESI A2 involves a mismatch between the number of the subject and the number of the verb. The difficulty arises when intervening prepositional phrases, appositives, or relative clauses separate the subject from the verb, as in: "The collection of blood samples were sent to the lab." Here, "collection" is singular, so the verb must be "was sent." To diagnose this error, mentally strip away the prepositional phrase and check whether the remaining subject-verb pair agrees.

Error Type 2: Dangling and Misplaced Modifiers

A dangling modifier occurs when the implied subject of a participial phrase does not match the grammatical subject of the main clause—for example, "After reviewing the chart, the medication was administered." The sentence implies that the medication reviewed the chart. The correction inserts the true agent: "After reviewing the chart, the nurse administered the medication." A misplaced modifier is positioned too far from the word it modifies, creating ambiguity: "The patient was referred to a specialist with chronic pain." Moving the modifier adjacent to "patient" resolves the ambiguity.

Error Type 3: Faulty Parallelism

Parallel structure requires that coordinated elements share the same grammatical form. A faulty construction such as "The protocol involves drawing blood, labeling specimens, and to transport them" mixes gerunds with an infinitive. The correction aligns all elements: "drawing blood, labeling specimens, and transporting them." On the HESI A2, parallelism errors frequently appear with correlative conjunctions (both…and, either…or, not only…but also), where the grammatical structure following each conjunction must be identical.

Error Type 4: Pronoun Reference and Case

Ambiguous pronoun reference arises when a pronoun could logically refer to more than one antecedent: "When the nurse spoke to the patient, she was concerned." Who was concerned—the nurse or the patient? The revision must eliminate ambiguity, often by replacing the pronoun with the intended noun. Pronoun case errors—using "whom" where "who" is needed or "I" where "me" is correct—are also tested, though less frequently.

SECTION 5

Detailed Error Taxonomy and Visual Classification

The following diagram organizes the most common HESI A2 grammar errors into a visual taxonomy. Each category is color-coded and includes representative signal words or patterns that help you identify the error type rapidly during the exam. Memorizing these signals substantially accelerates your elimination of incorrect answer choices.

The four major categories—Agreement, Modifiers, Structure, and Clarity—account for nearly all errors tested on the HESI A2 Grammar section. Structure-related errors appear most frequently (~30%), with agreement and modifier errors each contributing approximately 25%.

Error Type	Signal Pattern	Quick Fix Strategy
Subject-verb disagreement	Prepositional phrase between subject and verb	Cross out the intervening phrase; match verb to true subject
Dangling modifier	Sentence begins with a participial phrase (-ing, -ed)	Ensure the noun immediately after the comma is the doer of the action in the phrase
Faulty parallelism	Series with "and," "or," or correlative conjunctions	Make all listed items the same grammatical form
Vague pronoun reference	"It," "this," "they" with no clear antecedent or two possible antecedents	Replace the pronoun with the specific noun it refers to
Wordiness / redundancy	Phrases like "due to the fact that," "in order to," "at this point in time"	Replace with concise equivalents: "because," "to," "now"

Common HESI A2 error patterns with diagnostic signals and correction strategies

SECTION 6

Worked Example: Selecting the Best Revision

Consider the following HESI A2-style question. We will apply the decision-tree methodology to select the best revision systematically.

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ORIGINAL SENTENCE

"Running through the emergency room, the gurney was pushed by the paramedic who was responding to the trauma, and they quickly assessed the patient's vitals."

Choosing the Best Revision

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Step 1 — Identify All Errors in the Original

Read the sentence carefully and catalogue each error. First, "Running through the emergency room, the gurney was pushed" contains a dangling modifier—the participial phrase "Running through the emergency room" modifies "the gurney," implying the gurney was running. Second, "they quickly assessed" introduces a vague pronoun—"they" has no clear singular antecedent (is it the paramedic or a team?). Third, the sentence is wordy and uses passive voice unnecessarily ("was pushed by the paramedic").

Three errors identified: dangling modifier, vague pronoun, passive voice/wordiness.
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Step 2 — Evaluate Answer Choice A

"Running through the emergency room, the paramedic pushed the gurney and they quickly assessed the patient's vitals." This revision fixes the dangling modifier by placing "the paramedic" immediately after the comma and converts to active voice. However, the vague pronoun "they" remains unresolved—it is unclear whether "they" refers to the paramedic alone or to additional staff.

Fixes modifier and voice, but vague pronoun persists. Eliminate.
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Step 3 — Evaluate Answer Choice B

"Running through the emergency room, the paramedic pushed the gurney and quickly assessed the patient's vitals." This revision places "the paramedic" as the subject of the main clause, resolving the dangling modifier. It removes the vague pronoun "they" entirely by making "the paramedic" the implied subject of both coordinated verbs ("pushed" and "assessed"). The passive voice is eliminated, and the sentence is concise. Check parallelism: "pushed the gurney" and "assessed the patient's vitals" are parallel verb phrases joined by "and"—correct.

All errors resolved. No new errors introduced. This is the strongest candidate.
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Step 4 — Evaluate Answer Choice C

"The gurney was pushed through the emergency room by the paramedic, who was running and quickly assessing the patient's vitals." This revision eliminates the dangling modifier and clarifies the pronoun, but it retains passive voice ("was pushed") and adds wordiness. It also creates an illogical image—the paramedic is simultaneously running and assessing vitals, which strains the meaning.

Grammatically acceptable but wordy and logically awkward. Inferior to B.
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Step 5 — Confirm the Best Revision

Run the surviving candidate (B) through all six decision-tree gates: Subject-verb agreement ("paramedic pushed" and "[paramedic] assessed"—both singular) ✓. Modifier placement (participial phrase correctly modifies "paramedic") ✓. Parallelism ("pushed...and...assessed") ✓. Pronoun clarity (no pronouns used) ✓. Conciseness and active voice ✓. No new errors introduced ✓.

Answer: Choice B is the best revision.

SECTION 7

Strategies, Strengths, and Common Pitfalls

Understanding common test-design patterns on the HESI A2 helps you avoid the traps that cost examinees the most points. The table below contrasts effective strategies with the pitfalls they address.

Effective Strategy	Common Pitfall It Addresses	Why It Matters on the HESI A2
Read every answer choice completely before selecting	Selecting the first answer that fixes the obvious error without checking for new ones	Distractors are designed to fix one error while introducing another; partial fixes are the most common trap
Identify the error type before reviewing choices	Relying on "what sounds right" rather than applying rules	Ear-based judgments fail when test writers use constructions that sound natural but are grammatically incorrect
Strip sentences to their structural core (subject + verb + object)	Being distracted by long, complex sentences with multiple clauses	Agreement and modifier errors are deliberately hidden inside lengthy sentences; reducing complexity exposes them
Prefer active voice and concise phrasing when choices are otherwise equal	Choosing a grammatically correct but unnecessarily wordy revision	The HESI A2 rewards clarity as well as correctness; the best answer is typically the most direct
Check every pronoun for a clear, single antecedent	Overlooking ambiguous "it," "this," or "they" references	Pronoun clarity is critical in healthcare communication where ambiguity can compromise patient safety

Effective strategies paired with the common pitfalls they prevent on HESI A2 revision questions

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KEY TAKEAWAY

Think of each answer choice as a clinical intervention with potential side effects. A medication that treats a headache but causes renal failure is not the best treatment. Similarly, a revision that corrects a dangling modifier but introduces a pronoun error is not the best answer. The optimal revision—like the optimal treatment—resolves the problem without causing new complications.

SECTION 8

Connection to Advanced Sentence-Level Analysis

The sentence-revision skills tested on the HESI A2 form the foundation for more advanced writing competencies you will encounter in graduate-level coursework, including scientific manuscript preparation, evidence-based practice writing, and clinical documentation. The table below maps HESI A2-level skills to their graduate-level extensions, demonstrating how mastering the fundamentals now prepares you for higher-order analytical tasks.

HESI A2 Skill	Graduate-Level Extension	Clinical/Academic Application
Fixing dangling modifiers	Constructing complex multi-clause sentences with precise modifier chains	Writing case reports and discharge summaries where every modifier must attach to the correct clinical entity
Correcting subject-verb agreement	Managing agreement in sentences with nested relative clauses and compound subjects	Writing research methods sections where compound subjects describe multi-variable experiments
Eliminating vague pronouns	Mastering cohesion devices (demonstrative reference, lexical chains) for multi-paragraph coherence	Ensuring literature reviews maintain clear reference chains across pages of cited studies
Choosing concise over wordy phrasing	Editing for information density in word-limited abstracts and grant proposals	Meeting strict word limits in NIH grant applications (e.g., 30-line specific aims pages)
Ensuring parallel structure	Constructing taxonomic lists, outcome measures, and multi-part hypotheses with rigorous parallelism	Writing inclusion/exclusion criteria in research protocols where each criterion must follow identical grammatical form

HESI A2 grammar skills mapped to graduate-level writing competencies

As you advance into clinical and research writing, the revision skills practiced here will become second nature. The difference is one of scale and stakes: on the HESI A2, you revise a single sentence from four options; in practice, you will revise your own multi-page documents where no answer key exists. Building a reliable internal editor now—by internalizing the decision-tree methodology and the error taxonomy—ensures that your professional prose will be both correct and clear from the first draft.

SECTION 9

Practice Problems

Question 1: CONCEPTUAL

Explain why a sentence can be grammatically correct yet still be a poor choice among revision options on the HESI A2. Provide an example of a grammatically correct sentence that fails the clarity standard.

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A grammatically correct sentence can still fail the clarity standard if it uses excessive passive voice, redundant phrasing, or ambiguous word order. For example, "The medication that had been previously prescribed by the physician to the patient for the condition was subsequently administered" is grammatically correct but fails the clarity test due to wordiness and buried agency. The HESI A2 evaluates both correctness and clarity simultaneously, so a revision that is both grammatically sound and concise—such as "The physician prescribed the medication for the patient's condition"—will always be the stronger choice. This dual standard reflects the professional reality that healthcare communication must be error-free and immediately comprehensible.

Question 2: BASIC CALCULATION

Which is the best revision of the following sentence? Original: "Each of the nurses are required to complete their certification by December." A) Each of the nurses is required to complete their certification by December. B) Each of the nurses is required to complete her or his certification by December. C) Each of the nurses are required to complete her or his certification by December. D) All nurses is required to complete their certification by December.

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The best revision is B. The pronoun "each" is singular and requires the singular verb "is," which eliminates choices C and D. Choice D also introduces a new subject-verb disagreement ("All nurses is"). Choice A correctly uses "is" but retains a pronoun-antecedent disagreement: "each" (singular) is paired with "their" (plural). Choice B resolves both errors by using "is" (singular verb) and "her or his" (singular pronoun matching the singular antecedent "each"). While contemporary style guides increasingly accept singular "they," the HESI A2 tests traditional Standard Written English, making B the strongest answer in this context.

Question 3: INTERMEDIATE

Select the best revision of the following sentence: Original: "Walking into the patient's room, the IV alarm was beeping loudly, and the nurse noticed that the tubing had become kinked which caused the flow to stop." A) Walking into the patient's room, the nurse heard the IV alarm beeping loudly and noticed the kinked tubing that had stopped the flow. B) The IV alarm was beeping loudly when walking into the patient's room, and the nurse noticed that the tubing had become kinked, stopping the flow. C) Walking into the patient's room, the nurse heard the IV alarm beeping loudly, and she noticed that the tubing had become kinked, which was causing the flow to stop. D) The nurse, walking into the patient's room, heard the loud beeping IV alarm and noticed the tubing had kinked which caused the flow stopping.

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The best revision is A. The original contains a dangling modifier ("Walking into the patient's room" illogically modifies "the IV alarm") and a restrictive relative clause error ("which caused the flow to stop" lacks a comma before "which" in nonrestrictive use). Choice A corrects the dangling modifier by placing "the nurse" as the subject immediately after the participial phrase, converts the wordy phrasing into concise parallel predicates ("heard...and noticed"), and uses "that had stopped the flow" as a clear restrictive modifier. Choice B shifts the dangling modifier to "when walking" but still attaches it to "the IV alarm." Choice C is grammatically acceptable but is wordier than A and uses two independent clauses where A achieves the same meaning more efficiently. Choice D has a missing comma before "which" and the awkward nominalization "the flow stopping." Therefore, A is the most correct and the clearest.

Question 4: APPLIED

A nursing student is writing a clinical report and drafts the following sentence: "The patient's blood pressure, along with their heart rate and respiratory rate, were recorded every fifteen minutes, and they showed significant improvement throughout the shift." Identify all errors, explain why each is problematic in a clinical documentation context, and write the best revision.

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The sentence contains three errors. First, subject-verb disagreement: the subject is "blood pressure" (singular), with "heart rate and respiratory rate" placed in a parenthetical phrase set off by commas ("along with" does not create a compound subject), so the verb should be "was recorded," not "were recorded." In clinical documentation, this error could lead a reader to question whether the writer intends the vitals to be treated individually or collectively. Second, "their" is ambiguous—does it refer to the patient's vitals or to the patient? Third, "they showed significant improvement" uses a vague pronoun that could refer to the vitals or to unspecified people. In a clinical context, such ambiguity could lead to misinterpretation of which parameters improved. The best revision: "The patient's blood pressure, along with the heart rate and respiratory rate, was recorded every fifteen minutes; all three vital signs showed significant improvement throughout the shift." This revision uses the correct singular verb, eliminates ambiguous pronouns by specifying "all three vital signs," and uses a semicolon to create a logical connection between the two related independent clauses.

Question 5: CRITICAL THINKING

Consider the following sentence and three proposed revisions: Original: "Not only did the researcher analyze the data but also published the findings in a peer-reviewed journal and presenting at a national conference." A) Not only did the researcher analyze the data, but she also published the findings in a peer-reviewed journal and presented at a national conference. B) The researcher not only analyzed the data but also published the findings in a peer-reviewed journal and presented at a national conference. C) The researcher analyzed the data, published the findings in a peer-reviewed journal, and presented at a national conference. All three revisions are grammatically correct. Argue which is the single best revision, considering not only grammatical correctness but also rhetorical effectiveness, emphasis, and the conventions of academic prose.

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While all three revisions are grammatically correct, Choice B is the best revision for a combination of grammatical, rhetorical, and stylistic reasons. The original sentence has two errors: faulty parallelism in the correlative conjunction pair ("analyze... published... presenting" mixes verb forms) and misplacement of "not only" before the auxiliary "did" rather than before the first parallel element. Choice A corrects the parallelism and adds a clarifying pronoun, but inserting "she" introduces a gendered assumption about the researcher and separates "not only" from the element it correlates with. Choice C eliminates the correlative conjunction entirely, producing a simple series that is clear and concise but loses the rhetorical emphasis that "not only...but also" provides—the construction signals that publishing and presenting were noteworthy achievements beyond the expected task of data analysis. Choice B is optimal because it places "not only" directly before "analyzed" (the first parallel element), making the correlative structure grammatically precise; it maintains three parallel past-tense verbs ("analyzed," "published," "presented"); it preserves the rhetorical emphasis of the correlative conjunction; and it avoids unnecessary pronouns. In academic prose, where acknowledging the scope of a researcher's contributions matters, the emphatic structure of Choice B communicates more than the plain series of Choice C.

SUMMARY

Lesson Summary

Summary

Choosing the best revision on the HESI A2 requires you to evaluate each answer choice against two simultaneous criteria: grammatical correctness (conformity with Standard Written English) and rhetorical clarity (unambiguous, concise communication). The five core principles—subject-verb agreement, modifier placement, parallel structure, pronoun clarity, and conciseness with active voice—form the diagnostic checklist you should apply to every answer choice.

Use the decision-tree method: read the original sentence, identify the error category, then run each candidate revision through all six checkpoints (agreement, modifiers, parallelism, pronoun reference, conciseness, and absence of new errors). Eliminate any revision that fails even one gate, and select the choice that passes all gates. Remember that the HESI A2 frequently includes distractor revisions that fix the most obvious error while introducing a subtler one—so reading every choice completely and applying systematic analysis, rather than relying on intuition, is essential for a high score.