Last year, I wrote about parallelism, a principle of good writing that requires series items to be similar in structure. If you start a series with a noun, all items in the series should be nouns. Likewise, adjectives should be paralleled by adjectives and verbs should be paralleled by verbs.

Recently, I've had to correct a lot of parallelism problems in my editing practice. If you're uncertain about parallelism in your own writing, read on.

This sentence, from my article above, contains a series of three parallel nouns:

...I would focus on the material, the keyboard, and the screen.

If I had written, "...I would be focused on the material, the keyboard, and would not be able to think clearly," I would have had two nouns and a verb phrase. This inconsistency is jarring to the reader, who expects the repetition of nouns in the series.

I could fix that lack of parallelism by revising the sentence:

"I would focus on the material and the keyboard and would not be able to think clearly." Of course, this is no longer a series, but the structure is now parallel and much clearer for the reader.

Test your knowledge of parallelism by taking this one-question quiz.