Choosing which sentence uses correct parallel structure depends on whether words joined by the same grammatical function also share the same grammatical form. Parallel structure makes writing clearer, more balanced, and easier to read by ensuring that coordinated ideas follow a consistent pattern. This guide explains how to recognize correct parallelism, repair common errors, and confidently compare similar sentences.
What Is Parallel Structure?
Parallel structure, also called parallelism, is the use of matching grammatical forms for ideas that have equal importance in a sentence. When two or more words, phrases, or clauses are connected, they should usually follow the same pattern Not complicated — just consistent. That's the whole idea..
Consider this sentence:
Maya likes reading, writing, and painting That alone is useful..
All three items are gerunds ending in -ing, so the sentence is parallel.
Now compare it with this version:
Maya likes reading, to write, and painting The details matter here..
The second item is an infinitive, while the other two are gerunds. The meaning remains understandable, but the structure is uneven.
Maya likes reading, writing, and painting is correct And that's really what it comes down to. Nothing fancy..
Parallelism is not about making every word look identical. It is about making connected elements perform the same grammatical role in a consistent way.
How to Determine Which Sentence Uses Correct Parallel Structure
To decide which sentence uses correct parallel structure, follow four steps:
- Find the joining word. Look for conjunctions such as and, or, but, nor, and yet.
- Identify the connected elements. Determine exactly which words, phrases, or clauses the conjunction joins.
- Name each grammatical form. Check whether the elements are nouns, verbs, adjectives, prepositional phrases, gerunds, infinitives, or clauses.
- Compare the forms. If the elements have equal importance, they should use compatible grammatical structures.
For example:
The committee will review the proposal, discuss the budget, and select a winner.
Each element is a verb phrase:
- review the proposal
- discuss the budget
- select a winner
Because all three begin with a base-form verb followed by an object, the sentence is parallel That's the part that actually makes a difference. Took long enough..
Incorrect:
The committee will review the proposal, discussing the budget, and to select a winner.
Corrected:
The committee will review the proposal, discuss the budget, and select a winner That alone is useful..
Parallel Words and Phrases
The simplest parallel structures connect individual words that share the same part of speech.
Incorrect:
The course is informative, engaging, and a challenge That's the whole idea..
The first two elements are adjectives, but the third is a noun phrase.
Correct:
The course is informative, engaging, and challenging.
All three elements are now adjectives.
Another correct version is possible if every element becomes a noun phrase:
The course offers information, engagement, and a challenge It's one of those things that adds up..
Both revisions are grammatically parallel. The best choice depends on the intended meaning and emphasis.
Common parallel patterns include:
- Nouns: honesty, patience, and courage
- Adjectives: quick, accurate, and reliable
- Verbs: plan, organize, and evaluate
- Gerunds: studying, practicing, and reviewing
- Infinitives: to listen, to respond, and to adapt
- Prepositional phrases: in the classroom, during lunch, and after school
- Dependent clauses: what she said, how she reacted, and why she left
Parallelism With Gerunds and Infinitives
A frequent parallel-structure error occurs when a sentence mixes gerunds and infinitives. Now, a gerund is a verb form ending in -ing that functions as a noun, such as reading. An infinitive usually consists of to plus the base verb, such as to read.
Incorrect:
Liam enjoys to cook, baking, and gardening.
Correct:
Liam enjoys cooking, baking, and gardening.
Another correct pattern uses infinitives consistently:
Liam planned to cook, to bake, and to garden over the weekend But it adds up..
The repeated word to may also be placed before the first verb when it clearly applies to the entire series:
Liam planned to cook, bake, and garden over the weekend That's the part that actually makes a difference..
That said, do not omit to when doing so creates ambiguity. Repetition can improve clarity and rhythm Simple, but easy to overlook..
Incorrect:
The team hopes to finish the report, present the findings, and writing recommendations.
Correct:
The team hopes to finish the report, present the findings, and write recommendations.
Here, to applies to all three infinitives: to finish, to present, and to write.
Parallel Structure After Correlative Conjunctions
Correlative conjunctions appear in pairs and require especially careful parallelism. Common pairs include:
- either...or
- neither...nor
- both...and
- not only...but also
- whether...or
The grammatical form following the second conjunction should generally match the form following the first.
Incorrect:
The instructor not only explained the rule but also gave practice questions Small thing, real impact..
This sentence is actually parallel because both parts contain a past-tense verb phrase: explained the rule and gave practice questions.
Now examine a faulty version:
The instructor explained not only the rule but also gave practice questions.
After not only comes a noun phrase, while after but also comes a verb phrase.
Correct:
The instructor not only explained the rule but also gave practice questions.
Or:
The instructor explained not only the rule but also the examples Surprisingly effective..
In the second version, both connected elements are noun phrases Not complicated — just consistent..
Another example:
Incorrect:
Applicants must either submit the form online or a printed copy by mail Small thing, real impact..
Correct:
Applicants must submit either the online form or a printed copy by mail.
Both alternatives are now noun phrases.
A different correct revision is:
Applicants must either submit the form online or mail a printed copy Worth keeping that in mind..
Both alternatives are now verb phrases.
Parallelism in Comparisons
Comparisons often use than or as. The items being compared should be logically and grammatically comparable.
Incorrect:
The salary of a nurse is often lower than a teacher.
This sentence compares a salary with a person.
Of course. Here is the continuation of the article.
Parallelism in Lists
One of the most common areas where parallel structure falters is the simple list. Think about it: when you present a series of items, they should all be grammatically aligned. Mixing different parts of speech or clause structures can create a jarring and unprofessional effect.
Incorrect:
For our team retreat, we need a location that offers hiking trails, where we can swim, and great food Not complicated — just consistent..
The first item is a noun phrase, the second is a clause, and the third is another noun phrase. This inconsistency disrupts the flow Easy to understand, harder to ignore. Simple as that..
Correct:
For our team retreat, we need a location that offers hiking trails, a swimming area, and great food.
Now, all three items are noun phrases, creating a smooth and logical list.
Another example:
Incorrect:
Her responsibilities include managing the social media account, to respond to customer inquiries, and creating weekly reports.
Correct:
Her responsibilities include managing the social media account, responding to customer inquiries, and creating weekly reports.
In the corrected version, all three items are gerund phrases (verb + -ing), which is the standard way to list actions after verbs like "include."
The Importance of Consistency
Mastering parallel structure is not merely a matter of strict grammar rules; it is the foundation of clear and effective communication. When your sentences are parallel, they are easier to read, more persuasive, and more memorable. This principle applies to all forms of writing, from academic papers and business reports to creative stories and casual emails Not complicated — just consistent..
By ensuring that the elements in your sentences logically match each other, you demonstrate precision and respect for your reader. This small grammatical detail has a significant impact on the overall professionalism and polish of your work. In the long run, parallel structure is a tool for achieving clarity, allowing your ideas to stand out without the distraction of awkward or confusing phrasing Nothing fancy..
