Recognize and correct modifiers and parallel structure issues (as tested) - Health Education Systems Admission Assessment HESI

SECTION 1

Historical Context & Motivation

The rules governing modifiers and parallel structure are not modern inventions imposed by standardized testing companies; they are deeply rooted in centuries of rhetorical theory and linguistic analysis. Classical rhetoricians recognized that a misplaced descriptive phrase could transform a command into an absurdity, and that balanced sentence structures enhanced persuasion. The formal codification of these principles in English grammar textbooks accelerated during the eighteenth and nineteenth centuries, when prescriptive grammarians sought to standardize the language for scientific, legal, and medical discourse. Today, nursing and health-science entrance examinations such as the HESI A2 test these conventions because ambiguity in clinical documentation can jeopardize patient safety. A dangling modifier in a medication order or a faulty parallel list in a treatment protocol creates precisely the kind of confusion that grammar rules were designed to prevent.

c. 350 BCE • Aristotle's Rhetoric

Aristotle catalogued techniques of clear, balanced expression in persuasive speech, laying the groundwork for what we now call parallel structure and proper modification.

1762 • Lowth's Short Introduction to English Grammar

Bishop Robert Lowth published the first widely adopted prescriptive English grammar, explicitly warning against 'wrong position of adverbs' and 'discordant' sentence elements—early labels for misplaced modifiers and faulty parallelism.

1918 • Strunk's Elements of Style

William Strunk Jr. codified 'Use parallel construction' as a cardinal rule, ensuring generations of American writers internalized balanced syntax as a marker of clarity and professionalism.

2002 • Launch of the HESI A2 Exam

Health Education Systems Incorporated introduced the A2 admission assessment, embedding grammar items—including modifier placement and parallelism—as gatekeeping criteria for nursing and allied-health programs.

The central question the HESI A2 grammar section asks you to answer is deceptively simple: Does every descriptive word, phrase, or clause clearly attach to the element it is intended to modify, and are coordinated elements cast in the same grammatical form? Mastering this question requires you to recognize several specific error types—dangling modifiers, misplaced modifiers, squinting modifiers, and breakdowns in parallel structure—and to select the revision that eliminates ambiguity without introducing new errors.

SECTION 2

Core Principles & Definitions

Before dissecting individual error types, it is essential to establish the foundational principles that underlie every HESI A2 modifier and parallelism question. These principles function as diagnostic heuristics: once internalized, they allow you to evaluate any sentence for structural soundness within seconds, a critical skill given the exam's time constraints.

Proximity Principle

A modifier should be placed as close as possible to the word or phrase it modifies. Spatial distance between modifier and target creates ambiguity, forcing the reader to infer the intended attachment.

Logical-Subject Rule

An introductory participial or infinitive phrase must share its implied subject with the grammatical subject of the main clause. When the implied subject is absent or mismatched, the modifier 'dangles.'

Coordinate Symmetry

Items joined by coordinating conjunctions (and, but, or, nor) or correlative conjunctions (either…or, not only…but also) must share the same grammatical form: noun with noun, infinitive with infinitive, clause with clause.

Single-Attachment Clarity

A modifier must attach unambiguously to one element. A 'squinting' modifier—one positioned between two possible targets—violates this principle and must be relocated so that only one reading is possible.

Consistency of Form in Series

When three or more items appear in a list or series, every item must mirror the grammatical structure of the first item. Mixing gerunds with infinitives, or noun phrases with clauses, disrupts parallelism.

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KEY TAKEAWAY

Think of a modifier as a label on a patient's IV bag: if the label is attached to the wrong bag—or dangling in mid-air attached to nothing—the consequences range from confusion to catastrophe. Similarly, parallel structure functions like the columns of a well-designed data table; when every entry in a column uses the same unit and format, interpretation is instantaneous. When formats clash, you have to stop and decode, wasting cognitive resources that should be spent on clinical reasoning.

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Visual Explanation: Modifier Attachment

The top panel shows correct modifier placement: the participial phrase 'Running to the ER' attaches to 'the nurse,' and the relative clause 'that reduces inflammation' sits directly after 'medication.' The bottom panel illustrates two common HESI A2 errors: a dangling modifier (the crash cart cannot run) and a misplaced relative clause (the patient is not what reduces inflammation).

The diagram above crystallizes the core diagnostic question for every modifier item on the HESI A2: Does the modifier sit next to the word it logically describes? When a participial phrase opens a sentence, the very next noun phrase after the comma must be the agent performing that action. When a relative clause follows a noun, readers assume it modifies that noun, not one mentioned three words earlier. Internalizing these attachment patterns transforms ambiguous constructions into transparent ones, which is precisely the skill the exam assesses.

SECTION 4

How Modifier and Parallelism Errors Work

Modifier Error Taxonomy

Modifier errors on the HESI A2 fall into three categories, each defined by the relationship between the modifier and its intended target. A dangling modifier occurs when the intended target is entirely absent from the sentence or appears in a grammatical position that prevents logical attachment. Consider 'After reviewing the lab results, the diagnosis was confirmed.' The participial phrase 'After reviewing the lab results' implies a human agent who performed the review, yet the grammatical subject of the main clause is 'the diagnosis'—an inanimate entity incapable of reviewing anything. The correction requires inserting the logical agent as the subject: 'After reviewing the lab results, the physician confirmed the diagnosis.'

A misplaced modifier is a word, phrase, or clause that is present in the sentence and attached to a target, but attached to the wrong target because of its position. The classic culprits are adverbs like 'only,' 'almost,' 'nearly,' and 'just,' whose meaning shifts dramatically depending on placement. 'The nurse only administered the medication to three patients' suggests the nurse did nothing but administer (no charting, no assessment). Moving 'only' to its proper position—'The nurse administered the medication to only three patients'—clarifies that the number of patients, not the nurse's actions, is being limited.

A squinting modifier sits between two possible targets, making it impossible to determine which element it modifies. 'Patients who exercise frequently recover faster' is ambiguous: does 'frequently' modify 'exercise' (they exercise often) or 'recover' (they recover often/quickly)? The fix is to reposition the adverb so that only one reading survives: 'Patients who frequently exercise recover faster.'

Parallelism Error Taxonomy

Parallel structure errors arise when coordinated or listed elements do not share the same grammatical form. The HESI A2 tests three primary patterns. First, series parallelism requires that every item in a list match: 'The treatment plan includes monitoring vitals, administering medications, and to educate the patient' breaks parallelism because the third item shifts from a gerund to an infinitive. The correction is 'monitoring vitals, administering medications, and educating the patient.' Second, correlative-conjunction parallelism mandates that the element following each half of a correlative pair be structurally identical. 'The patient either needs surgery or physical therapy' is faulty because 'either' precedes a verb phrase while 'or' precedes a noun phrase. Repositioning yields 'The patient needs either surgery or physical therapy.' Third, comparison parallelism requires that items on both sides of comparison words (than, as) share the same grammatical form: 'Reading patient charts is more important than to memorize drug names' should be 'Reading patient charts is more important than memorizing drug names.'

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HESI A2 TEST TIP

When you encounter a sentence with a list connected by 'and,' 'or,' or a correlative pair, immediately identify the grammatical form of the first item (gerund? infinitive? noun?). Then scan each subsequent item for a mismatch. This rapid-check strategy catches more than 80% of parallelism errors on the exam.

SECTION 5

Detailed Breakdown: Error Types & Corrections

This decision flowchart guides you through the two-branch diagnostic process tested on the HESI A2. Start at the top, determine whether the sentence involves a list (parallelism branch, left) or a modifying phrase (modifier branch, right), then follow the yes/no nodes to identify the specific error type.

Error Type	Erroneous Sentence	Corrected Sentence	Why It's Wrong
Dangling modifier	To improve patient outcomes, the protocol was revised.	To improve patient outcomes, the committee revised the protocol.	The infinitive phrase implies a human agent, but the subject is 'the protocol.'
Misplaced modifier	She almost treated every patient in the ward.	She treated almost every patient in the ward.	'Almost' should modify 'every patient,' not 'treated.'
Squinting modifier	Charting carefully improves accuracy.	Careful charting improves accuracy. / Charting improves accuracy carefully.	'Carefully' could modify 'charting' or 'improves.' Repositioning resolves the ambiguity.
Series parallelism	Nurses must assess, plan, and be implementing interventions.	Nurses must assess, plan, and implement interventions.	The third item shifts to a progressive form; all three must be base infinitives.
Correlative parallelism	Not only did the drug reduce fever but also inflammation.	The drug reduced not only fever but also inflammation.	After 'not only' we have a clause; after 'but also' we have a noun. Both must be nouns (or both clauses).

Common HESI A2 modifier and parallelism error types with corrections

SECTION 6

Worked Example: HESI-Style Question

Below is a representative HESI A2 grammar question that combines a modifier issue with a parallelism trap, exactly as the exam sometimes does. Working through it step by step illustrates the diagnostic approach from the flowchart.

HESI A2 Practice Stem

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Step 1 — Read the Stem

The question presents: "Hoping to reduce infection rates, hand-washing protocols, sanitizing equipment, and to wear personal protective equipment are priorities for the nursing staff." You are asked to identify and correct the error.
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Step 2 — Identify the Modifier

The sentence opens with a participial phrase: 'Hoping to reduce infection rates.' Under the logical-subject rule, the grammatical subject of the main clause must be the entity doing the hoping. The grammatical subject here is 'hand-washing protocols, sanitizing equipment, and to wear personal protective equipment'—a compound noun phrase consisting of inanimate concepts. Protocols do not 'hope,' so the introductory phrase is a dangling modifier.

Dangling modifier detected: the participial phrase has no logical human subject.
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Step 3 — Check for Parallelism in the Series

The compound subject contains three items: (1) 'hand-washing protocols' (noun phrase), (2) 'sanitizing equipment' (gerund phrase), and (3) 'to wear personal protective equipment' (infinitive phrase). According to the consistency-of-form principle, all items must share the same structure. Item 3 is an infinitive, while items 1 and 2 are noun/gerund forms. This is a parallelism error.

Parallelism error detected: 'to wear' breaks the gerund/noun pattern.
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Step 4 — Construct the Correction

To fix both errors simultaneously, insert a human agent as the subject and convert all list items to the same form. A corrected version reads: 'Hoping to reduce infection rates, the nursing staff prioritizes hand-washing protocols, equipment sanitization, and personal protective equipment use.' Now the participial phrase attaches to 'the nursing staff' (who can indeed hope), and all three list items are noun phrases.

Corrected: 'Hoping to reduce infection rates, the nursing staff prioritizes hand-washing protocols, equipment sanitization, and personal protective equipment use.'
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Step 5 — Verify

Read the revised sentence aloud. The participial phrase 'Hoping to reduce infection rates' now logically modifies 'the nursing staff.' The three prioritized items—'hand-washing protocols,' 'equipment sanitization,' and 'personal protective equipment use'—are all noun phrases. No ambiguity remains.

Both the dangling modifier and the parallelism error are resolved.

SECTION 7

Strengths, Limitations & Common Traps

Strategy	Strengths	Limitations / Pitfalls
Proximity Check	Fast to apply; catches misplaced single-word adverbs (only, nearly, almost) instantly.	Does not work for absolute phrases and sentence-level adverbs (e.g., 'Fortunately, the test was negative'), which can legally modify the entire clause.
Logical-Subject Test	Reliable for dangling modifiers; simply ask 'Can the subject perform the action in the opening phrase?'	Can produce false positives when the subject is metonymic (e.g., 'the study found'—technically the researchers found, but this construction is accepted in academic prose).
Form-Matching for Parallelism	Mechanical and reliable; just label each item's part of speech and look for mismatches.	May lead students to 'over-correct' stylistic variation that is grammatically acceptable (e.g., combining short and long noun phrases is fine as long as the form category matches).
Reading Aloud	Engages auditory processing; awkward constructions often 'sound wrong' even before you identify the rule.	Unreliable for non-native speakers or for subtle squinting modifiers, where both readings sound plausible.

Diagnostic strategies with their strengths and limitations

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KEY TAKEAWAY

No single strategy is infallible on the HESI A2; the strongest approach is a two-pass system. On your first pass, read for meaning—does the sentence say something logical? On your second pass, apply the mechanical tests: check modifier proximity, verify the logical subject of introductory phrases, and label the grammatical form of every item in a list or correlative pair. Think of it as the difference between a nurse's clinical gestalt (first pass) and a systematic head-to-toe assessment (second pass): both are essential, and combining them yields the most accurate diagnosis.

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Connection to Advanced Grammar & Clinical Writing

While the HESI A2 tests modifier and parallelism skills at the sentence level, these same principles scale to paragraph- and document-level structures that you will encounter in graduate health-science programs. Cohesion—the quality of logical connectedness across sentences—depends heavily on consistent modifier placement. When every sentence in a clinical note places modifiers predictably, the reader builds a mental model of the patient's status without backtracking. Conversely, a paragraph in which modifiers drift unpredictably forces the reader to re-parse sentences, increasing cognitive load and the likelihood of clinical error.

HESI A2 Level	Graduate/Professional Level
Identify a dangling modifier in a single sentence.	Ensure that every introductory clause across a multi-paragraph care plan logically attaches to the correct agent, especially when switching between nurse, patient, and physician as actors.
Correct a misplaced 'only' or 'almost.'	Position limiting adverbs precisely in medication orders (e.g., 'Administer only 5 mg' vs. 'Only administer 5 mg') where misplacement changes dosing implications.
Fix a list with mixed gerunds and infinitives.	Maintain parallel structure across bullet-pointed nursing interventions in electronic health records, policy documents, and research manuscripts to satisfy APA style guidelines.
Recognize a squinting modifier in isolation.	Audit discharge instructions for ambiguous adverbs that patients might misinterpret (e.g., 'Take the medication lying down' — take it while lying down, or it will make you lie down?).

How HESI A2 modifier/parallelism skills scale to professional practice

Mastering these conventions at the HESI A2 level thus serves a dual purpose: it earns you a competitive score on the admission exam, and it lays the grammatical foundation for the precise, unambiguous clinical writing that graduate programs expect from day one.

SECTION 9

Practice Problems

Question 1: CONCEPTUAL

Explain the difference between a dangling modifier and a misplaced modifier. Provide a one-sentence example of each using a healthcare context.

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A dangling modifier has no logical word in the sentence for it to modify; the intended target is entirely absent or appears in a grammatical position that prevents attachment. For example, 'After inserting the IV, the patient was monitored' dangles because the patient did not insert the IV—the nurse did, but the nurse is absent from the sentence. A misplaced modifier, by contrast, has a logical target present in the sentence but is positioned next to the wrong word, creating an unintended meaning. For example, 'The nurse almost checked every vital sign' misplaces 'almost' so that it modifies 'checked' (suggesting the nurse nearly performed the action but did not) rather than 'every' (which conveys that the nurse checked most but not all signs). The key diagnostic difference is whether the intended target is missing (dangling) or merely distant (misplaced).

Question 2: BASIC

Identify and correct the error in the following sentence: 'Designed to lower blood pressure, the pharmacist recommended the new medication.'

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The sentence contains a dangling modifier. The participial phrase 'Designed to lower blood pressure' implies that its subject was designed for that purpose, but the grammatical subject is 'the pharmacist'—a human being, not something designed to lower blood pressure. The intended target is 'the new medication,' which must be repositioned as the subject of the main clause. A corrected version reads: 'Designed to lower blood pressure, the new medication was recommended by the pharmacist.' Alternatively, you can restructure the sentence entirely: 'The pharmacist recommended the new medication, which was designed to lower blood pressure.' Both revisions ensure that the modifier attaches to the correct noun.

Question 3: INTERMEDIATE

Which of the following sentences is free of both modifier and parallelism errors? (A) 'The treatment plan includes monitoring vitals, to administer medications, and educating patients.' (B) 'Walking briskly, the patient's heart rate increased.' (C) 'The physician not only ordered bloodwork but also a CT scan.' (D) 'After reviewing the chart, the nurse identified three risk factors, documented her findings, and contacted the attending physician.'

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The correct answer is (D). In option (A), the series breaks parallelism: 'monitoring' (gerund), 'to administer' (infinitive), 'educating' (gerund)—the second item should be 'administering.' In option (B), the participial phrase 'Walking briskly' dangles because the grammatical subject is 'the patient's heart rate,' which cannot walk. In option (C), the correlative pair 'not only…but also' lacks parallel structure: 'not only' is followed by a verb phrase ('ordered bloodwork') while 'but also' is followed by a noun phrase ('a CT scan'). A correction would be 'ordered not only bloodwork but also a CT scan.' Option (D) is correct: the introductory phrase 'After reviewing the chart' attaches logically to 'the nurse,' and the three predicates—'identified,' 'documented,' and 'contacted'—are all past-tense verbs in parallel form.

Question 4: APPLIED

A nursing student writes the following discharge instruction: 'To prevent infection, the wound should be cleaned daily, apply antibiotic ointment, and covered with a sterile bandage.' Identify all errors and rewrite the sentence so that it is grammatically correct and clinically clear.

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This sentence contains two errors. First, there is a dangling modifier: the infinitive phrase 'To prevent infection' implies a human agent who performs preventive actions, but the grammatical subject 'the wound' is not a person. Second, the series breaks parallelism: 'should be cleaned' (passive voice), 'apply' (active imperative), and 'covered' (passive participle missing the auxiliary 'should be') are three different verb forms. A corrected version is: 'To prevent infection, the patient should clean the wound daily, apply antibiotic ointment, and cover it with a sterile bandage.' This revision places a human subject ('the patient') after the infinitive phrase, resolving the dangling modifier, and casts all three actions as active-voice base verbs following 'should,' restoring parallel structure. This version is also clinically superior because it directly instructs the patient, making the discharge instructions actionable.

Question 5: CRITICAL THINKING

Consider the sentence: 'Researchers who study stress frequently develop innovative therapies.' This sentence contains a squinting modifier. First, explain the two possible interpretations. Then, provide two distinct revisions—one for each intended meaning—and discuss how the position of 'frequently' resolves the ambiguity in each case. Finally, reflect on why squinting modifiers pose a unique danger in clinical research reports.

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The adverb 'frequently' sits between two verbs—'study' and 'develop'—and could modify either one. Interpretation A: the researchers study stress on a frequent basis (frequently modifies 'study'). Interpretation B: the researchers develop innovative therapies on a frequent basis (frequently modifies 'develop'). Revision for Interpretation A: 'Researchers who frequently study stress develop innovative therapies.' Moving 'frequently' directly before 'study' locks it to that verb. Revision for Interpretation B: 'Researchers who study stress frequently develop innovative therapies' is still ambiguous; a clearer option is 'Researchers who study stress develop innovative therapies frequently,' placing the adverb at the end of the clause it modifies. In clinical research reports, squinting modifiers are uniquely dangerous because they can alter the reported frequency of outcomes or interventions. If a systematic review states that 'patients who exercised regularly reported reduced pain,' a reader cannot tell whether 'regularly' describes the exercise regimen or the pain-reporting schedule. Such ambiguity could lead clinicians to misinterpret evidence-based recommendations, potentially affecting treatment protocols. This is why rigorous academic and clinical writing demands unambiguous modifier placement.

SUMMARY

Lesson Summary

Summary

This lesson addressed the two families of grammatical error most frequently tested in the HESI A2 Grammar section: modifier errors and parallel structure errors. Modifier errors come in three varieties: a dangling modifier occurs when the intended target of a participial or infinitive phrase is absent from the sentence or occupies a position that blocks logical attachment; a misplaced modifier occurs when a word or phrase sits next to the wrong target; and a squinting modifier occurs when an adverb is positioned between two possible targets, generating two plausible interpretations. The diagnostic rule for all three is the proximity principle: place every modifier as close as possible to the element it describes, and verify that the grammatical subject of the main clause can logically perform the action named in any introductory phrase.

Parallel structure errors arise when items joined by coordinating conjunctions (and, but, or) or correlative conjunctions (either…or, not only…but also) do not share the same grammatical form. The fix is to identify the form of the first item—noun, gerund, infinitive, clause—and recast every subsequent item to match. On the HESI A2, applying a two-pass diagnostic strategy (first read for meaning, then apply mechanical tests) will maximize both speed and accuracy. Beyond the exam, these skills directly transfer to clinical documentation, where ambiguous modifiers and inconsistent list structures can compromise patient safety.