Which sentence uses parallel structure correctly in a technical list?
Parallel structure means that items in a list use the same grammatical form. In option B, all three items are noun phrases: authentication, authorisation, event logging. Options A, C, and D mix noun phrases with infinitives ("to authorise", "to log") or verb phrases ("logs events"), breaking the parallel pattern. In technical writing — README files, API docs, user stories — lists must be grammatically consistent. A quick test: read each item with the introductory clause: "The system handles authentication ✓ / authorisation ✓ / event logging ✓."
2 / 5
A tech spec compares two approaches. Which version uses parallel structure in the comparison?
Option A is parallel: both clauses follow the pattern "[subject] is [adjective] to [verb]" — "REST is simpler to implement" / "GraphQL offers more flexibility." Option B switches tense ("is offering"). Option C mixes a noun phrase subject with an adjective fragment ("has more flexible"). Option D shifts to passive voice mid-sentence, breaking the symmetry. In technical comparisons ("X is faster, while Y is more scalable"), keep both sides in the same voice and tense.
3 / 5
You're writing a PR description with three bullet points about what a function does. Which version is parallel?
Option B uses the imperative (base) verb form for all three bullets: Validates / Transforms / Returns. This is the standard pattern for describing what code does in PR descriptions, README usage sections, and API docs. Option A ends with a passive sentence ("A response object is returned"). Option C starts with a gerund ("Validating") but switches to base verbs. Option D starts with a noun phrase. Pick one grammatical form and maintain it throughout the entire list.
4 / 5
Which sentence correctly uses a parallel correlative pair (either/or, both/and, not only/but also)?
"not only scalable but also reliable" is correct. With correlative conjunctions (not only/but also, either/or, both/and), the words or phrases that follow each conjunction must be in the same grammatical category. In option B: scalable (adjective) / reliable (adjective) — perfect parallel. Option A places "scalable" (adjective) against "it also has reliability" (clause). Option C places "is scalable" (verb phrase) against "reliability" (noun). Option D breaks the structure with "additionally." The rule: whatever grammatical form follows "not only" must follow "but also" too.
5 / 5
A code comment describes three responsibilities of a class. Which version is grammatically parallel?
Option C uses the third-person singular verb form for all three items: manages / retries / emits. This is parallel. Option A mixes gerunds ("managing"), noun phrases ("retry logic"), and an infinitive ("to emit"). Option B mixes "manages" (verb), "retrying" (gerund), and "metric emission" (noun phrase). Option D mixes a noun phrase, infinitive, and gerund. When writing class-level doc comments or JSDoc descriptions, pick one consistent form — typically the base verb ("Returns…", "Manages…", "Emits…") — and apply it to every item in the list.