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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.
Definition of parallel for English Language Learners. : 1  a way in which things are similar : a shared quality or characteristic. : 2  something that is equal or similar. : 3  any one of the imaginary circles on the surface of the Earth that are parallel to the equator and that are shown as lines on maps.