Failure to use parallel structure

Within a sentence, say similar things in similar ways. Here are some examples of faulty parallelism (saying similar things in different ways):

example: The lion was large, powerful, and had an appearance that was frightening.

revision: The lion was large, powerful, and frightening.

example: Antelope learn to run from lions and avoidance of leopards.

revision: Antelope learn to run from lions and to avoid leopards.

In the first example, three similar elements (the adjectives large, powerful, and frightening) were not grammatically similar: frightening appeared in an adjective clause, the other two did not. To revise, we expressed all three as simple adjectives. In the second example, to run is an infinitive and avoidance is a noun. To revise, we changed avoidance into an infinitive.


example: With a decline in soil organic matter, structural deterioration begins to happen in the soil which reduces water infiltration, poor oxygenation and increases erosion.

revision: When soil organic matter declines, soil structure deteriorates, reducing water infiltration, reducing soil oxygenation, and increasing erosion.

Parallelism can be a powerful tool. Whereas unintentional repetition of words, phrases, or clauses can confuse the reader, intentional repetition can build rhythm and focus attention.