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.
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.
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
Logical-Subject Rule
Coordinate Symmetry
Single-Attachment Clarity
Consistency of Form in Series
Visual Explanation: Modifier Attachment
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.
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.'
Detailed Breakdown: Error Types & Corrections
| 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). |
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.
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. |
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?). |
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.
Practice Problems
Lesson 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.