Question

What is parallel structure?
using details that go in chronological order to show how events unfolded in a certain way
pairing information that is similar and different to highlight the similarities or differences to make a point
• pairing events to show what happened that caused something else to happen
using a pattern of repeated words or phrases to show that pieces of information are of equal importance

Answer 1

Parallel structure (also called parallelism) means using the same grammatical form for two or more elements in a sentence so those elements are shown as equal in importance.

Of the options you gave, the closest is the last one, but more precisely: parallel structure is using the same pattern of words, phrases, or clauses (not just repeating words) so the items line up grammatically.

Quick examples
- Correct: She likes hiking, swimming, and biking.
- Incorrect: She likes hiking, to swim, and biking.
- Correct with correlative conjunctions: He will either call you or send an email.
- Incorrect: He will either call you or sending an email.

Why it matters: parallelism improves clarity, balance, and rhythm in writing. The other options you listed describe chronology, comparison/contrast, or cause-and-effect — those are different organizational techniques, not the definition of parallel structure.