Parallelism
Also known as: parallel structure, parallel construction
Parallelism is the principle that items in a series or in a paired construction must share the same grammatical form. "She likes hiking, swimming, and running" is parallel; "She likes hiking, swimming, and to run" is not.
Parallelism requires that elements playing the same role in a sentence take the same grammatical shape. If the first item in a list is a gerund, every item must be a gerund; if the first is an infinitive phrase, the rest must be infinitive phrases. The rule applies to nouns, verbs, phrases, and whole clauses alike — anything joined by a coordinating conjunction or arranged in a series.
Faulty parallelism usually appears in three places. Lists are the most common: "The job requires patience, creativity, and being organized" mixes two nouns with a gerund phrase, and should read "patience, creativity, and organization." Correlative conjunctions — not only/but also, either/or, neither/nor, both/and — must be followed by matching structures, so "He not only wrote the report but also the summary" is wrong; move the verb outside the pair to get "He wrote not only the report but also the summary." Comparisons need parallel terms too: "Her scores were higher than her brother" compares scores to a person and should read "higher than her brother's."
Beyond correctness, parallelism is a rhetorical tool. Repeating a structure creates rhythm and emphasis, which is why it anchors so much memorable prose and oratory — Lincoln's "of the people, by the people, for the people" works precisely because the three prepositional phrases match. In analysis of literature, deliberate parallel construction is treated as an element of syntax that controls pace and signals which ideas the writer wants weighted equally.
Parallelism is a reliable point-scorer on standardized tests. The ACT English section tests it under organization, unity, and cohesion, and the CLT grammar and writing section tests it through sentence structure questions. AP English Literature approaches it from the other direction, asking you to explain the effect of parallel syntax in a passage rather than to correct it. A dependable tactic on multiple-choice items: read each list item back onto the words that introduce the list, and pick the answer where every item fits.
Key takeaways
- Parallelism means that items in a series or paired construction share the same grammatical form.
- Faulty parallelism most often appears in lists, after correlative conjunctions, and in comparisons.
- Correlative pairs such as not only/but also must be followed by matching structures.
- Parallel structure also creates rhythm and emphasis, which is why writers use it deliberately.
- To check a list, read each item back onto the words that introduce it and confirm all of them fit.