Use parallel structure. | Varsity Tutors

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Historical Context & Motivation

Long before anyone wrote a grammar textbook, speakers and writers discovered that balanced sentence structures are easier to understand and more persuasive. Parallel structure—the practice of using the same grammatical pattern for elements that share the same function—has been a cornerstone of powerful communication for thousands of years. Ancient orators relied on it to rally crowds, and modern writers use it to create prose that flows with clarity and rhythm. Understanding the history of this technique reveals why it remains one of the most essential conventions of standard English.

~400 BCE

Greek Rhetoric & Isocolon

Greek rhetoricians like Gorgias and Aristotle championed isocolon—clauses of equal length and structure—as a key tool for persuasion and beauty in speech.

~55 BCE

Cicero's Orations

Roman statesman Cicero used parallel phrases to devastating effect in his speeches, establishing patterns that influenced Latin prose for centuries.

1776

The Declaration of Independence

Thomas Jefferson employed parallel clauses—"He has…He has…He has…"—to build a cumulative case against King George III, demonstrating the persuasive power of repetition and balance.

1963

"I Have a Dream" Speech

Martin Luther King Jr.'s iconic repetition of "I have a dream that one day…" became one of the most famous examples of parallelism in the English language.

Today

Modern Standard English

Style guides, standardized tests, and college writing programs all emphasize parallel structure as a fundamental rule of clear, correct prose.

From ancient Athens to modern classrooms, the principle remains the same: when ideas are equal in importance, they deserve equal grammatical treatment. So what exactly does parallel structure look like in practice, and how can you apply it to your own writing? That is the question this lesson answers.

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Core Principles & Definitions

At its heart, parallel structure means that items joined by a coordinating conjunction, listed in a series, or compared with correlative conjunctions should all share the same grammatical form. If the first item in a list is a gerund (an -ing verb form), every other item should be a gerund too. If you start with an infinitive phrase, the rest should follow suit. Breaking this pattern creates a jarring bump in your sentence—like a song where the rhythm suddenly falls apart.

Matching Grammatical Form

Coordinated elements—words, phrases, or clauses joined by and, but, or, nor—must use the same part of speech or phrase type.

Lists & Series

Every item in a series should be structured identically. Mix a noun with a clause, and the sentence stumbles. Keep them all as nouns, all phrases, or all clauses.

Correlative Conjunctions

Pairs like either…or, neither…nor, not only…but also, both…and demand that whatever follows the first word matches the form of what follows the second.

Comparisons

When comparing two actions or ideas with than or as, the structures on both sides of the comparison word should mirror each other.

✦ KEY TAKEAWAY

Think of parallel structure like lanes on a highway. Each lane carries traffic in the same direction, at roughly the same speed. If one lane suddenly turned into a dirt path, drivers would crash. Similarly, when one item in your list shifts grammatical form—say, from a noun to an entire clause—your reader's brain "crashes" trying to process the mismatch. Keep every lane (every item) the same type, and traffic (meaning) flows smoothly.

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Visual Explanation

The top example shows three items in a series all using the same gerund form (swimming, hiking, running), which creates parallel structure. The bottom example mixes a gerund, an infinitive phrase, and a full clause—three mismatched forms that break the pattern.

Notice how the parallel version feels natural and rhythmic—your brain processes each item at the same pace. In the non-parallel version, you have to mentally shift gears with every item, which slows comprehension and sounds awkward. The green boxes in the diagram all share the same shape and label because their grammatical form matches. In the red-highlighted version, the boxes differ in size and color because each item is a different grammatical form. Your goal as a writer is to keep every box the same color.

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How Parallel Structure Works

Parallel structure operates at three levels of sentence construction: words, phrases, and clauses. At each level, the rule is the same: match the grammatical form. Let's examine each level and the specific triggers—coordinating conjunctions, correlative conjunctions, comparisons, and lists—that demand parallelism.

Level 1 — Word-Level Parallelism

When you join single words with and, but, or or, every word should be the same part of speech. For example, "The coach is strict, fair, and motivating" coordinates three adjectives. Writing "The coach is strict, fair, and a motivator" breaks the pattern by slipping a noun into a list of adjectives.

Level 2 — Phrase-Level Parallelism

Phrases—groups of words without a subject–verb pair—should match in type. "She enjoys reading novels, painting landscapes, and composing music" uses three gerund phrases. If you switched the last item to "and she composes music," you'd have two gerund phrases and one independent clause—a mismatch.

Level 3 — Clause-Level Parallelism

Entire clauses can be parallel too, especially in complex or compound sentences. Consider Lincoln's "government of the people, by the people, for the people." Each prepositional phrase follows the same pattern: preposition + "the people." When clauses share a repeated structure, the effect is powerful and memorable.

Trigger: Correlative Conjunctions

Correlative conjunctions always come in pairs: either…or, neither…nor, not only…but also, and both…and. Whatever grammatical structure follows the first conjunction must follow the second. "She is not only talented but also hardworking" pairs adjective with adjective. Writing "She is not only talented but also works hard" pairs an adjective with a verb phrase—a parallelism error.

This diagram shows the three levels at which parallelism operates. At each level, the solid box shows the correct matching form, while the dashed red box shows a common mismatch error.

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Common Parallelism Errors & How to Fix Them

Now that you understand the rule, let's look at the mistakes that appear most often in student writing—and on standardized tests. Recognizing these patterns will help you fix errors in your own work and identify correct answers on exams.

Five common parallelism errors with corrected versions

Error Type	Non-Parallel (✗)	Parallel (✓)
Mixed verb forms	I like to swim, hiking, and to ride bikes.	I like swimming, hiking, and riding bikes.
Mixed parts of speech	The job requires patience, skill, and being creative.	The job requires patience, skill, and creativity.
Faulty correlative	She not only sings but also is a dancer.	She not only sings but also dances.
Mismatched clauses	The teacher said that we should study and to do homework.	The teacher said that we should study and that we should do homework.
Faulty comparison	Writing essays is harder than to take a quiz.	Writing essays is harder than taking a quiz.

💡 TEST-TAKING TIP

On standardized tests like the SAT and ACT, parallelism questions often appear in "improving sentences" or "editing" sections. The quickest way to spot the error is to underline each item in the list or pair and check whether they share the same grammatical form. If one item looks structurally different from the others, that's your error.

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Worked Example

Let's walk through the process of identifying and correcting a parallelism error step by step, the same way you would on an essay revision or an exam.

Fixing a Faulty Parallel Sentence

Step 1 — Read the Original SentenceOriginal: "The manager told the team to arrive on time, that they should dress professionally, and preparing reports before the meeting."

Step 2 — Identify the Coordinated ElementsThe sentence contains a list of three things the manager told the team. They are connected by commas and "and." Underline each item: (1) to arrive on time (2) that they should dress professionally (3) preparing reports before the meeting.

Step 3 — Diagnose the MismatchItem 1 is an infinitive phrase (to arrive). Item 2 is a that-clause (that they should dress). Item 3 is a gerund phrase (preparing). All three use different grammatical forms—this is a clear parallelism error.

Error: three different grammatical forms in one list.

Step 4 — Choose a Consistent FormPick the form that sounds most natural. Since "told the team to" leads smoothly into infinitives, rewrite every item as an infinitive phrase.

Step 5 — Rewrite the SentenceRevised: "The manager told the team to arrive on time, to dress professionally, and to prepare reports before the meeting." Now all three items are infinitive phrases. The sentence is balanced, clear, and correct.

Corrected: "The manager told the team to arrive on time, to dress professionally, and to prepare reports before the meeting."

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Strengths, Pitfalls & Stylistic Effects

Parallel structure is not just a grammar rule you follow to avoid losing points—it is a powerful stylistic tool. When used well, it can make your writing more persuasive, more memorable, and more elegant. However, there are also a few pitfalls to watch out for.

Balancing the benefits and risks of parallel structure

Strengths	Pitfalls to Avoid
Creates rhythm and flow, making prose easier and more enjoyable to read.	Overusing parallelism for every sentence can make writing feel monotonous and formulaic.
Clarifies relationships between ideas by giving equal ideas equal weight.	Forcing parallelism on ideas that are not actually equal can mislead the reader.
Makes arguments more persuasive—readers trust balanced sentences.	Long parallel lists (5+ items) can become tedious. Keep lists concise.
Improves memorability—people remember phrases like "of the people, by the people, for the people."	Incorrect "false parallelism"—making items look parallel when they are logically different—can confuse meaning.

✦ KEY TAKEAWAY

Parallel structure is like the bass line in a song—it provides a steady, predictable foundation that lets the melody (your ideas) shine. But if the bass just plays the same note over and over without variation, the song gets boring. Use parallelism strategically at key moments—in thesis statements, in lists, in conclusions—rather than hammering it into every single sentence.

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Connection to Advanced Rhetoric & Style

Parallel structure at the sentence level is the foundation, but as you advance as a writer, you'll encounter more sophisticated forms of parallelism used in rhetoric and literary analysis. Understanding these connections now will prepare you for AP-level coursework and college writing.

Advanced rhetorical techniques built on parallel structure

Technique	Definition	Example
Anaphora	Repeating the same word(s) at the start of successive clauses or sentences.	"We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields."
Antithesis	Placing contrasting ideas in parallel structures to sharpen the contrast.	"Ask not what your country can do for you—ask what you can do for your country."
Tricolon	A series of three parallel elements, building to a climax.	"Life, liberty, and the pursuit of happiness."
Chiasmus	Reversing the structure of parallel clauses in an ABBA pattern.	"When the going gets tough, the tough get going."

Each of these advanced techniques relies on the same basic principle you've learned in this lesson: matching grammatical forms for parallel elements. Anaphora adds repetition of the opening words. Antithesis places opposing ideas side by side. Tricolon harnesses the power of three. Chiasmus flips the order for a mirror effect. Mastering basic parallelism now gives you a foundation for all of these more advanced moves.

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Practice Problems

PROBLEM 1 — CONCEPTUAL

In your own words, explain why the following sentence lacks parallel structure: "The dog enjoys fetching sticks, chasing squirrels, and when it swims in the lake."

PROBLEM 2 — BASIC CALCULATION

Rewrite this sentence using correct parallel structure: "The scholarship committee values academic achievement, participating in community service, and that applicants show leadership."

PROBLEM 3 — INTERMEDIATE

Identify and correct the parallelism error involving a correlative conjunction: "The new policy will either reduce wait times or it will be improving customer satisfaction."

PROBLEM 4 — APPLIED

You are writing the opening of a persuasive essay about school lunch reform. Rewrite the following thesis statement to use effective parallel structure: "Schools should provide healthier lunches because good nutrition improves focus, it helps to reduce absences, and students who eat well are more likely to perform better academically."

PROBLEM 5 — CRITICAL THINKING

Read the following passage and revise it so that it uses parallel structure at both the sentence and paragraph level, creating an effective tricolon (series of three) for rhetorical impact: "Education opens doors to opportunity. It is also something that gives people the power to change their communities. And when people are educated, the whole nation benefits from that."

SUMMARY

Lesson Summary

Parallel structure means using the same grammatical form for elements that are joined by coordinating conjunctions (and, but, or), correlative conjunctions (either…or, not only…but also), comparisons (than, as), or listed in a series. This rule applies at three levels: words (match parts of speech), phrases (match phrase types like gerund or infinitive), and clauses (match clause patterns).

To spot and fix errors, underline each coordinated element and check whether they share the same grammatical form. Choose one consistent form—nouns, gerunds, infinitives, or clauses—and revise all items to match. Beyond correctness, parallel structure is a rhetorical tool that creates rhythm, clarity, and persuasive power. Techniques like anaphora, antithesis, tricolon, and chiasmus all build on this foundation, making parallelism one of the most versatile skills a writer can master.