Introduction to Parallelism


Parallelism refers to a series of two or more identical grammatical structures joined by a coordinating conjunction (usually and or or). To be parallel, words must have the same form; word groups must have the same components in the same forms.

Being parallel means having the same form. Though form has broader meaning, we notice form in spelling. For example, the word accomplishments is a noun in the plural form, which we notice because of the –s ending. Parallel words might include degrees and honors, both plural nouns. Parallel words and word groups are similar in the role they play in the sentence (nouns in a list, verbs of the same tense, phrases) and thus similar in the way they are spelled.


The video illustrates parallelism with pencils. Pencils in a stack or line demonstrate how parallelism works with and, which applies to items in a series or lists. The pencils facing each other demonstrate how parallelism works with or, which applies when contrasting pairs or items in a series.

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Parallelism requires making words and word groups that play similar roles in the sentence have the same form.

In a sentence, each word has a role to play. Those roles are called parts of speech and parts of sentences. Words and word groups that play the same role should have the same form. Form is conveyed through spelling.

The most common parallelism errors involve verb forms that either end in -ing (gerunds) or appear after to (infinitives). Faulty parallelism is the error that results when items in a series are not all in the same grammatical form.

Consider this sentence:


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The sentence is about three activities that Sylvia likes. Since the activities play the same role in the sentence (predicates), they need to have the same form. Look at the underlined words from the sentence in a list:

By putting the words in a stack, it is easy to see that to collect is spelled differently than the others. To collect is in the wrong form, and this is faulty parallelism. To collect is an infinitive; reading and listening are gerunds, which are verbs that end in –ing and play the role of nouns. To correct the error, change to collect to collecting.


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Now, the three activities Sylvia likes are parallel. They have the same role in the sentence, the same form, the same spelling.

The example focuses on parallelism within a sentence. But, parallelism can also apply within paragraphs. Anytime you are trying to make readers understand how ideas are similar or different, help them by making the form of each word or word group the same.


The study pages focus on parallelism in sentences. As you read through the study pages and practice with LearningCurve before taking the post-test (if assigned), try to picture the words or word groups that should be parallel in a stack like the bulleted list above; or, think about how the pencils facing each other would appear over the contrasting words or word groups.

Don’t forget to work smartly!