Parallel structure, also called parallel construction and parallelism, is a method of formatting written elements so that they correspond to each other structurally. Parallel structure can be applied to any closely related elements; however, it is most often applied to headings, bulleted lists, numbered lists, lists in sentences, and tightly coupled phrases or sentences.
Parallel structure serves both functional and stylistic purposes.1 It is functional because it helps readers identify the relationship between the elements. It is stylistic because people enjoy looking at, listening to—and reading—things that have symmetry.
There are many ways to create parallel structure.2 For example, you can format all of the items as complete sentences or phrases beginning with the same type of word. Here is a numbered list in which each item is a complete sentence starting with a regular verb.
Complete the following four steps to ensure reimbursement of your travel expenses:
- Obtain a reimbursement form from the HR department.
- Complete the reimbursement form and attach your receipts.
- Deliver the reimbursement form and your receipts to the HR department within ten business days of returning from your trip.
- Contact HR if you have not received your reimbursement check within thirty days.
Here is an example of a group of phrases in a sentence in which each phrase begins with a preposition.
The kittens hid behind the sofa, under the coffee table, above the bookshelves, inside the cabinets, and below the sink.
My next post will explore ways to use parallel structure to add a professional polish to headings in reports, articles, chapters, and blog posts.
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1. Bryan A. Garner, Garner’s Modern English Usage (New York: Oxford University Press, 2016), 670–671.
2. The Chicago Manual of Style, 17th ed. (Chicago: University of Chicago Press, 2017), 5.42–5.45.