In grammar, parallelism, also known as parallel structure or parallel construction, is a balance within one or more sentences of similar phrases or clauses that have the same grammatical structure. The application of parallelism affects readability and may make texts easier to process.
Compare the following examples:
|"She likes cooking, jogging, and to read."||"She likes cooking, jogging, and reading."
"She likes to cook, jog, and read."
|"He likes baseball and running."||"He likes playing baseball and running."
"He likes to play baseball and to run."
|"The dog ran across the yard, jumped over the fence, and sprinted away."||"The dog ran across the yard, jumped over the fence, and sprinted down the alley."|
All of the above examples are grammatically correct, even if they lack parallelism: "cooking", "jogging", and "to read" are all grammatically valid conclusions to "She likes", for instance. The first nonparallel example has a mix of gerunds and infinitives. To make it parallel, the sentence can be rewritten with all gerunds or all infinitives. The second example pairs a gerund with a regular noun. Parallelism can be achieved by converting both terms to gerunds or to infinitives. The final clause of the third example does not include a definite location, such as "across the yard" or "over the fence"; rewriting to add one completes the sentence's parallelism.
Parallelism is often used as a rhetorical device. Examples:
- "The inherent vice of capitalism is the unequal sharing of blessings. The inherent virtue of Socialism is the equal sharing of miseries." — Winston Churchill, House of Commons, 22 October 1945
- "Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and the success of liberty." — John F. Kennedy, Presidential Inaugural Address
- "... and that government of the people, by the people, for the people, shall not perish from the earth." — Abraham Lincoln, Gettysburg Address
- "We have petitioned, and our petitions have been scorned; we have entreated, and our entreaties have been disregarded; we have begged, and they have mocked when our calamity came. We beg no longer; we entreat no more; we petition no more. We defy them." — William Jennings Bryan, Cross of Gold speech
- Gary Blake and Robert W. Bly, The Elements of Technical Writing, pg. 71. New York: Macmillan Publishers, 1993. ISBN 0020130856
- For the point about processing, see Carlson, Katy. Parallelism and Prosody in the Processing of Ellipsis Sentences. Routledge, 2002, pp. 4–6.
- "Rhetorical Figures in Sound: Parallelism". American Rhetoric. Archived from the original on 15 January 2018.
- "Vice of Capitalism". International Churchill Society. Retrieved 15 January 2018.
- Faulty Parallelism, Nipissing University