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Parallelism (grammar) 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 improves writing style and readability, and is thought to make sentences easier to process.
A Parallel Construction Problem: the False Series. A common problem in writing today is the false series. It happens when a writer combines three or more seemingly related elements in a series, but the syntax is wrong. When you get the sentence right, you're said to be using parallel construction.