ERROR 7: FAULTY PARALLELISM
Definition
Parallelism (also called parallel structure or parallel construction) requires that words, phrases, or clauses in a series or comparison be expressed in the same grammatical form. When a sentence lists or compares items, each item should have the same grammatical structure. If the first item is a noun, all items should be nouns. If the first item is an infinitive (to run), all items should be infinitives. If the first item is a gerund (running), all items should be gerunds.
Faulty parallelism occurs when the items in a list or comparison are grammatically inconsistent — some are nouns, some are infinitives, some are gerunds, some are clauses, and so on. This inconsistency makes sentences feel awkward and difficult to read. Parallelism is especially important in sentences using correlative conjunctions (both…and, either…or, neither…nor, not only…but also) and in comparisons using ‘than.’
Proper parallelism not only satisfies grammatical rules but also creates a pleasing rhythm in prose. The lack of parallelism often signals to readers that the writer is not in full control of their sentence structure.
Rules
RULE: All items in a list connected by ‘and,’ ‘or,’ or ‘but’ must use the same grammatical form (all nouns, all verbs, all infinitives, all gerund phrases, etc.).
RULE: Correlative conjunctions (both…and, either…or, neither…nor, not only…but also, whether…or) must connect grammatically parallel elements.
RULE: In comparisons, the elements being compared must be in the same grammatical form.
RULE: When a parallel series begins with ‘to’ (the infinitive marker), either include ‘to’ before each verb in the series or include it only before the first one — do not mix.
Examples
✗ She likes hiking, to swim, and running on trails. [Gerund, infinitive, gerund — inconsistent]
✓ She likes hiking, swimming, and running on trails. [All gerunds]
✗ His goals are to graduate, getting a job, and he wants to travel.
✓ His goals are to graduate, to get a job, and to travel. [All infinitives]
✗ The proposal was rejected because of its high cost, poor timing, and because the board didn’t trust the team.
✓ The proposal was rejected because of its high cost, poor timing, and the board’s lack of trust in the team.
✗ Not only is she a talented writer, but also she paints beautifully.
✓ Not only is she a talented writer, but she is also a beautiful painter. [Parallel verb phrases after each conjunction]
✗ The manager is responsible for training new employees, to oversee daily operations, and he must handle complaints.
✓ The manager is responsible for training new employees, overseeing daily operations, and handling complaints. [All gerunds]
✗ I prefer reading novels rather than to watch television.
✓ I prefer reading novels rather than watching television. [Both gerunds]
✗ The seminar covered how to write a business plan, presentation techniques, and networking effectively.
✓ The seminar covered writing a business plan, delivering effective presentations, and networking. [All gerunds]
✗ Either you submit the application today or you should send an email tomorrow.
✓ Either you submit the application today or you send an email tomorrow.
✗ She is more interested in the results than how the process worked.
✓ She is more interested in the results than in the process.
✗ The key factors are a strong economy, educating children well, and if healthcare is affordable.
✓ The key factors are a strong economy, high-quality education, and affordable healthcare. [All noun phrases]
Extended Dialogue
In this dialogue, journalism students Ana and Ben are reviewing their feature article before submitting it to the student newspaper.
Ana: Ben, listen to this sentence I wrote about the new student center: ‘The center offers tutoring, to use computer labs, and study rooms.’ Does that sound right?
Ben: It sounds a bit off. Let me think. ‘Tutoring’ is a gerund, ‘to use’ is an infinitive, and ‘study rooms’ is just a noun. They’re all different.
Ana: So how do I fix it?
Ben: Pick one form and apply it to everything. The simplest would be a list of nouns: ‘The center offers tutoring services, computer lab access, and study rooms.’ Or gerunds: ‘The center offers tutoring, computing, and studying in quiet rooms.’
Ana: What about this sentence: ‘The director said the renovation would improve safety, make the building energy-efficient, and that it would attract more students.’
Ben: Same problem. ‘Improve safety’ is an infinitive phrase, ‘make the building energy-efficient’ is an infinitive phrase, but then ‘that it would attract more students’ is a clause. They don’t match.
[Note: The first two items use bare infinitive phrases; the third switches to a ‘that’ clause. All three should be parallel infinitive phrases.]
Ana: Fix it like this: ‘The director said the renovation would improve safety, increase energy efficiency, and attract more students.’
Ben: Perfect. All three are infinitive phrases: ‘would improve… would increase… would attract.’ The eye flows right through them.
Ana: What about correlative conjunctions? I’ve always struggled with those. I wrote: ‘Not only the students are happy, but also the faculty has shown support.’
Ben: With ‘not only…but also,’ whatever comes after ‘not only’ must be the same structure as what comes after ‘but also.’ Here, ‘not only’ is followed by ‘the students are happy’ — a full clause. So ‘but also’ must also be followed by a full clause.
Ana: Which it is — ‘the faculty has shown support.’
Ben: True, but the placement of ‘not only’ is awkward — it should come right before what’s being emphasized. Better: ‘Not only have students expressed happiness, but faculty have also shown their support.’
Ana: Parallelism is really about rhythm, isn’t it? Good parallelism sounds balanced.
Ben: Exactly. When a sentence has parallel structure, it flows. When it doesn’t, the reader feels the bump even if they can’t explain why.
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