Parallel Structure: Make Your Sentences Flow

Reviewed by the Grammarlyzer Editorial Team · Our Review Standards · Published January 22, 2026 · Updated June 13, 2026

Keep lists and comparisons balanced for professional clarity.

Quick Answer

Parallel structure means using the same grammatical pattern in a series.

Fix it by making all list items match in form.

Memory Trick: If one item starts with a verb, all should.

🔑 Key Takeaway

Balanced structure makes writing easier to read and more persuasive.

Where Parallel Structure Is Required

Parallelism isn't optional decoration — certain structures demand it. Whenever items share a slot in the sentence, they must share a grammatical form.

Structure The items must match in… Example
Lists joined by and / or part of speech / phrase type reading, writing, and editing (all -ing)
Correlatives (not only…but also, either…or) the form after each half not only fast but also affordable
Comparisons (than / as) both sides of the comparison driving is cheaper than flying
Bulleted / numbered lists the opening word of each item Managed… Designed… Led… (all past-tense verbs)

Common Mistakes

❌ Incorrect:

She likes reading, swimming, and to bike.

✓ Correct:

She likes reading, swimming, and biking.

The first two items are gerunds (-ing), so the third must match. Switching to the infinitive "to bike" breaks the pattern.
❌ Incorrect:

The role involves analyzing data, report writing, and to present findings.

✓ Correct:

The role involves analyzing data, writing reports, and presenting findings.

Three different forms (gerund phrase, noun phrase, infinitive) become three matching gerund phrases. Job descriptions and résumés are where this matters most.
❌ Incorrect:

The plan is not only ambitious but also it is risky.

✓ Correct:

The plan is not only ambitious but also risky.

After "not only … but also," both halves must take the same form. "Ambitious" is an adjective, so the second half should be the adjective "risky," not a full clause.
❌ Incorrect:

I'd rather walk than driving.

✓ Correct:

I'd rather walk than drive.

Comparisons with "than" need matching forms on both sides — base verb "walk" pairs with base verb "drive," not the gerund "driving."

🎯 Test Your Knowledge

1. Make it parallel: "The job requires planning, budgeting, and ___ the team."

2. "She works efficiently, carefully, and ___."

3. "The phone is not only sleek but also ___."

4. "He came here to rest and ___."

5. Résumé bullets: "Managed the budget, ___ the campaign, and led the team."

See It Live: Check a Sentence With Our Engine

Don't just trust the rule—test it. The grammar engine below checks your text directly in your browser. The starter sentence mixes a gerund with an infinitive—make the list parallel, or paste your own to compare.

A parallel rewrite: The workshop covers writing clearly, editing quickly, and presenting confidently. All three items are now -ing phrases, so the list reads in one consistent pattern.

Honest limits: the engine reliably flags the mechanics—spelling, agreement, punctuation—but whether a sentence is clear is a judgment call. Use the parallel structure guidance above to decide if the structure actually serves the reader.

Frequently Asked Questions

Why does "She likes running, swimming, and to bike" sound wrong?

The first two items are gerunds (running, swimming) but the third switches to an infinitive (to bike), breaking the pattern. Make them all match: "running, swimming, and biking."

Does parallel structure apply to bullet-point lists in resumes?

Yes. Each bullet should begin with the same grammatical form, usually an action verb, such as "Managed," "Designed," and "Led" rather than mixing verbs with noun phrases like "Workflow design."

Do "not only ... but also" require parallel structure?

Yes. Correlative conjunctions like not only/but also, either/or, and both/and need matching grammatical forms on each side. Write "not only fast but also affordable," not "not only is it fast but also affordable."

Word Origins & Etymology

Parallel comes from Greek 'parallelos' (side by side), from 'para' (beside) + 'allelos' (each other). Parallel structure means using the same grammatical pattern for items in a list or comparison.

Non-parallel: 'She likes reading, to swim, and cooking.' Parallel: 'She likes reading, swimming, and cooking.'

🔗 The Connection

Parallel structure is one of the most powerful tools in rhetoric. Martin Luther King Jr.'s 'I Have a Dream' speech uses parallel structure extensively for emotional impact.

Real-World Examples

✅ Parallel:

She likes reading, swimming, and cooking.

All gerunds (-ing) — consistent pattern
❌ Not Parallel:

She likes reading, to swim, and cooking.

Mixed forms: gerund, infinitive, gerund — inconsistent
✅ Parallel:

The job requires analyzing data, writing reports, and presenting findings.

All gerund phrases — professional and clear
❌ Not Parallel:

The job requires analyzing data, report writing, and to present findings.

Three different grammatical structures — confusing
✅ Parallel (correlative):

She not only sings beautifully but also plays piano.

Correlative conjunctions require parallel structure after each part
💡 Rule:

Items joined by and/or/but, or in lists, must use the same grammatical form (all nouns, all verbs, all phrases).

Consistency is the key to parallel structure

Why Do People Confuse Them?

Non-parallel structure sounds 'clunky' but is hard to identify because the meaning is usually clear despite the grammatical mismatch. Writers often don't notice the inconsistency because they focus on content rather than grammatical form. Reading lists aloud reveals parallelism problems immediately.

For more practice, see Dangling Modifiers and Run.

Related Articles

Parallel Structure for Clean Final Copy

In business documents, parallel structure is one of the clearest signals of professional editing. Bullet lists in reports, pitch decks, and job postings are the most visible battleground: every item in a list should begin with the same grammatical form. If the first bullet starts with an action verb ("Design the workflow"), every bullet should do the same — not switch to a noun phrase ("Workflow design") or a sentence fragment ("Designing workflows is important"). Readers process parallel lists faster because the grammatical form itself becomes a reliable cue, reducing the cognitive load of parsing each item. Broken parallelism in a client-facing document signals inattention to detail at exactly the moment you want to project competence.

In academic writing, parallel structure matters most in thesis statements, topic sentences, and the presentation of research findings. A thesis that lists three claims must present all three in matching grammatical form: "This paper argues that social media increases anxiety, reduces attention span, and distorts political perception" — three verb phrases flowing from the same subject. Mixing forms ("increases anxiety, attention span reduction, and political perception is distorted") forces the reader to mentally reparse each element. Literature reviews that present multiple studies in parallel constructions also read more smoothly and demonstrate that the writer has synthesized sources rather than simply strung together summaries.

The most common errors in parallel structure cluster around three patterns. The first is inconsistent verb form in lists, usually caused by drafting items at different times without reviewing the whole list afterward. The second is parallelism broken by embedded clauses — a list item that contains a relative clause ("that improves morale") next to items without one, creating asymmetry. The third is faulty parallelism in correlative conjunctions: "not only... but also," "either... or," and "both... and" require grammatically matching elements on both sides. Writers often write "not only is it fast but also affordable" when the correct form is "not only fast but also affordable."

The Parallel Structure Test

Read each element in a series and ask: could I substitute this word or phrase for any other item in the list without changing the grammatical structure of the sentence? If the answer is yes, the list is parallel. If swapping items requires restructuring the sentence, at least one item is out of alignment and needs revision.

Style Questions About Parallel Structure

What does "parallel structure" actually mean in grammar?

Parallel structure means that words, phrases, or clauses joined by conjunctions or presented as a series share the same grammatical form. If you start a series with a gerund (swimming), each item should be a gerund (swimming, hiking, cycling — not "to cycle" or "cycling and then you run"). The principle applies at every level of the sentence: words in a pair, items in a list, clauses in a compound sentence, and elements on both sides of correlative conjunctions like "both...and" or "either...or." The requirement is consistency of grammatical category, not identical length or wording.

How do I fix a broken parallel list quickly?

The fastest method is to identify the dominant grammatical form in your list — the form used by most items — then convert every outlier to match. If five of seven bullet points start with past-tense verbs and two start with nouns, convert the two nouns to verbs. If you cannot decide on a dominant form, choose the one that feels most natural for all items and rewrite every item from scratch using that form. Avoid trying to "split the difference" by partially rewriting items, as this often creates new inconsistencies. Review the complete list one final time after revision to confirm uniformity.

Do correlative conjunctions require parallel structure?

Yes, and this is where parallelism errors are most persistent. Correlative conjunctions — both/and, either/or, neither/nor, not only/but also — require that the element immediately following each part of the pair be grammatically identical. "She is both talented and works hard" is incorrect because "talented" is an adjective and "works hard" is a verb phrase. The correct form is "She is both talented and hardworking" (two adjectives) or "She both has talent and works hard" (two verb phrases). The test is to mentally remove one half of the pair and check whether the sentence still works with each element independently.

Is it a parallelism error to mix infinitives and gerunds?

Yes, in most contexts. Mixing "to run" (infinitive) and "swimming" (gerund) within the same list breaks parallel structure: "She enjoys to run, swimming, and cycling" is non-parallel. Correct versions are "She enjoys running, swimming, and cycling" or "She wants to run, to swim, and to cycle." There is one exception: when each infinitive in a list shares the same "to" at the start ("to run, swim, and cycle"), the structure is conventionally parallel even though "to" appears only once. This elliptical form is standard in formal writing and is not considered a parallelism violation.

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