Parallel structure
Parallel structure (parallelism) means that items in a list, comparison or paired conjunction share the same grammatical form: 'She enjoys hiking, swimming and cycling.' Faulty parallelism (mixing forms, as in 'hiking, to swim and cycled') breaks the pattern, jars the reader, and counts against grammatical accuracy in IELTS Writing.
The rule
Where parallel structure applies
Lists
A, B and C, all in the same form
The job involves planning events, managing budgets and writing reports.
Paired conjunctions
both X and Y / either X or Y / neither X nor Y
The proposal is neither realistic nor affordable.
Comparisons
Xthan/asY (matching forms)
Renting in Lisbon is now almost as expensive as buying.
Prefer / would rather
prefer X to Y / would rather X than Y
She prefers marking essays to invigilating exams.
Correlatives with verbs
not only X but also Y (matching forms)
The scheme not only trains farmers but also guarantees their prices.
Inside a sentence
The job involvesplanningA: -ing formevents,managingB: -ing formbudgetsandandwritingC: -ing formreports.
The schemesubjectnot onlynot onlytrainsX: verb + -sfarmersbut alsobut alsoguaranteesY: verb + -stheir prices.
- subject
- main verb
- key word
How to use parallel structure
What is parallel structure?
Whenever a sentence coordinates items (with and, or, but, than, or a paired conjunction) readers expect each item to arrive in the same grammatical shape: noun with noun, gerund with gerund, clause with clause. That expectation is parallel structure, and meeting it is what makes a sentence feel balanced.
Break the pattern and the sentence stumbles even if every word is individually correct: 'The city is lively, affordable and has friendly people' forces the reader to re-parse mid-list. Repair it by matching the forms: 'lively, affordable and friendly.'
- Good managers delegate clearly, listen patiently and decide quickly.three matching verb + adverb pairs
- The course covers listening, reading and note-taking.three matching nouns
- The flat is bright, quiet and costs very little.→ bright, quiet and cheap, three adjectives
How do you keep lists parallel?
Pick the grammatical form of the first item and keep it for every later item: gerund with gerund, noun with noun, clause with clause. Mixed lists usually appear when a writer bolts on one extra idea in a hurry; the third item is where parallelism most often dies.
Length may vary as long as the skeleton repeats. A list of three verb-ing phrases can mix items of three words and thirteen; readers track the pattern, not the word count.
- The retreat offers hiking, kayaking and stargazing.three gerunds
- The report recommends raising the levy, tightening inspections and publishing the results.same skeleton, different lengths
- The course teaches grammar, essay writing and how to pronounce difficult words.→ grammar, essay writing and pronunciation
How do both…and, either…or and neither…nor demand parallelism?
Paired (correlative) conjunctions are a frame: whatever grammar follows the first half must follow the second half too. 'Either postpone the trip or cancel it' balances verb against verb; 'both the syllabus and the timetable' balances noun against noun.
The commonest slip is planting the first marker too early, so that it captures the verb: 'She both speaks Arabic and French' puts a verb after both but a bare noun after and. Slide the marker along until the halves match: 'She speaks both Arabic and French.'
- You can either pay the fine online or contest it in person.verb phrase balances verb phrase
- The museum is popular with both tourists and local families.
- The scheme will neither help commuters nor cyclists.→ will help neither commuters nor cyclists
How does parallelism work in comparisons?
Than and as are balancing scales: put the same kind of phrase on each side. 'Working in a team is better than working alone' weighs gerund against gerund; slipping an infinitive onto one side ('better than to work alone') tips the scale.
Comparisons must also match logically, not just grammatically. 'Rents in Hanoi are lower than Singapore' accidentally compares rents with a city; the parallel version compares rents with rents: 'lower than in Singapore'.
- Studying with a partner suits me better than studying alone.gerund balances gerund
- Rents in Hanoi are lower than in Singapore.rents compared with rents
- Travelling by metro is quicker than the bus.→ quicker than taking the bus
Why does parallelism matter for IELTS style?
Parallelism sits exactly where the IELTS Writing criteria meet: a broken list is a grammar error under Grammatical Range and Accuracy, while a controlled one improves Coherence and Cohesion at no extra cost. Long Band 8 sentences are usually long because parallelism holds them together, not because the writer risked extra clauses.
It also protects you under time pressure. A parallel skeleton written into your plan (verb, verb, verb) almost fills itself in, and each repetition is a structure you have effectively proofread once already.
- A good thesis names the problem, takes a position and previews the reasons.parallel triple in an introduction
- The council promised to widen the cycle lanes, resurface the ring road and pedestrianise the old town.three parallel infinitive complements
- Remote work saves time, cuts costs and employees are happier.→ and boosts morale, keep verb + object
Common mistakes with parallel structure
Find what is wrong in each one, then open it to check.
1The app is fast, reliable and costs almost nothing.What's wrong? Show the fix
The app is fast, reliable and cheap.
A list of adjectives cannot absorb a verb phrase; the third item must match the first two.
2He likes reading novels, to watch documentaries and photography.What's wrong? Show the fix
He likes reading novels, watching documentaries and taking photographs.
One list, one form: the gerund pattern set by 'reading' must run to the end.
3She both plays the piano and the violin.What's wrong? Show the fix
She plays both the piano and the violin.
Both must sit directly before the first of the two matching items; here it wrongly captures the verb.
4Working night shifts is harder than to work weekends.What's wrong? Show the fix
Working night shifts is harder than working weekends.
Than balances matching forms: gerund against gerund.
5The manual explains how to install the software and connecting the printer.What's wrong? Show the fix
The manual explains how to install the software and how to connect the printer.
The second item must repeat the how-to-infinitive skeleton, not switch to a gerund.
6You can pay either by card or cash.What's wrong? Show the fix
You can pay either by card or in cash.
Whatever follows either (a prepositional phrase) must follow or as well; alternatively move the marker; 'by either card or cash'.
Practise
Write your own
Write a sentence of your own with parallel structure, about you, your studies or your town.
Parallel structure in IELTS
Speaking
- Build Part 3 answers on spoken triples: 'It saves time, cuts costs and reduces stress.' Three parallel verbs sound fluent, are easy to keep accurate at speed, and give an answer the sense of completion examiners respond to.
- In Part 2, describe with parallel adjectives rather than drifting into mismatched clauses: 'crowded, chaotic and completely unforgettable' lands harder than three separate sentences and shows control of coordination.
Writing
- Draft Task 2 thesis statements as parallel skeletons: 'This essay argues that governments should tax sugary drinks, restrict advertising and fund school sport.' The parallel frame carries a long sentence safely: range without risk.
- In Task 1, repeat the clause shape when contrasting trends ('Sales of laptops rose steadily, while sales of desktops declined sharply') so the reader compares data, not grammar. Matching skeletons are a quiet cohesion device the criteria reward.