Grammatical parallelism, parallel structure, parallel construction, parallel form (1)

Grammatical parallelism is also called parallel structure, parallel construction, and parallel form. It is the use of equivalent syntax to array equivalent ideas.

An example of parallelism

Winston Churchill (photo) used parallelism to great effect in his speeches. For example, in a speech to the House of Commons on May 13, 1940, he used this memorable sentence:

“I would say to the House as I said to those who have joined this government: I have nothing to offer but blood, toil, tears and sweat.”

Every object of the preposition but is a noun: blood, toil, tears and sweat. This use of parallel structure made it easy for his listeners (and later, readers) to understand the logic of the sentence. The structure also made the sentence more pleasing aesthetically and more persuasive.

In contrast, consider what would have happened if Mr. Churchill had for some reason used the gerund weeping instead of tears:

…blood, toil, weeping and sweat.

The logic is the same; the sentence conveys roughly the same message. And the grammar is correct in a narrow sense: a gerund can be functionally equivalent to a noun. (It is correct to say, “I have nothing to offer but weeping.”)

But “blood, toil, weeping and sweat” sounds wrong, because the gerund stands out against the nouns. It breaks up the parallel structure and confuses the listener or reader. And it is less pleasing aesthetically.

Or, imagine if Mr. Churchill had used the infinitive to toil instead of the noun toil.

…blood, to toil, tears and sweat.

Again, the logic is the same. Again, the grammar is correct in a narrow sense: an infinitive can be functionally equivalent to a noun. (It is correct to say, “I have nothing to offer but to toil.”)

But “blood, to toil, tears and sweat” sounds wrong, because the infinitive stands out against the nouns. It breaks up the parallel structure and confuses the listener or reader. And it is less pleasing aesthetically.

The Takeaway: Take advantage of the power of grammatical parallelism (also called parallel structure, parallel construction, and parallel form). Parallelism can help make your prose clear, pleasant and persuasive.