Grammar / usage: Parallel structure
Subtopic: Section D · Grammar
How to structure your answer
Rule: when two or more items are joined by a coordinating conjunction ('and', 'or', 'but'), correlative conjunction ('either … or', 'not only … but also'), or by comparison ('rather than', 'as much as'), they must share the same grammatical form — all noun phrases, all verb phrases, all gerunds, all infinitives.
Approach: identify the conjunction; check the items on either side; force them into the same grammatical form. The repair is usually quick — change a gerund to an infinitive, or rephrase a noun phrase to match.
What an examiner expects: rule stated cleanly; corrected sentences with the parallel items underlined; a one-line justification.
Common pitfalls: (1) mixing gerunds and infinitives ('She likes hiking and to swim'); (2) breaking parallelism in lists of three or more; (3) breaking parallelism across correlative pairs ('not only … but also').
Detailed model answer
123 words · target 100 words · 8 min
Rule: Items joined by coordinating conjunctions or listed in a series must share the same grammatical form — noun with noun, gerund with gerund, infinitive with infinitive, clause with clause.
Worked examples: 'She enjoys reading, writing and painting' (not to paint: keep gerunds parallel). 'The course teaches students to think critically, to write clearly and to argue persuasively' (parallel infinitives). 'He is wise, honest and courageous' (not has courage).
Quick check:
- The job involves planning, scheduling and (to coordinate/coordinating) tasks. coordinating
- She came not to complain but (helping/to help). to help
- He is known for his diligence, his honesty and (he speaks well/his eloquence). his eloquence
- The plan was bold, simple and (it could be executed/executable). executable
- I prefer hiking to (swim/swimming). swimming
What an examiner expects to see
- Rule: items joined by conjunctions must share grammatical form.
- Lists of nouns: all nouns.
- Lists of verbs: all in the same form (all -ing, all infinitive, all simple).
- Correlative pairs: 'either … or', 'neither … nor', 'not only … but also', 'both … and' — items after each member must be the same form.
- Comparison: 'rather than X, Y' — X and Y must be the same form.
- Headings and bullet points also follow parallelism rules.
- Repair: change one item to match the others, not the other way around in isolation.
- Watch articles: 'a book, a pen and the eraser' — drop or repeat articles consistently.
- Watch prepositions: 'interested in art, music and in literature' — repeat or drop consistently.
- Practice sentences below.
Concrete cases, schemes and judgments
- Wrong: 'She likes hiking, swimming and to read books.' Right: 'She likes hiking, swimming and reading books.' (all gerunds.)
- Wrong: 'He is not only a writer but also teaches.' Right: 'He is not only a writer but also a teacher.' (noun balances noun.)
- Wrong: 'The minister promised to cut taxes, reducing inflation and creating jobs.' Right: 'The minister promised to cut taxes, reduce inflation and create jobs.' (all infinitives.)
- Wrong: 'We were tired, hungry and feeling angry.' Right: 'We were tired, hungry and angry.' (all adjectives.)