Parallel structure refers to the way you organize and present your ideas to the reader when you have a group of two or more items in a sentence. These items could be words, phrases, or clauses. To avoid confusion on the part of your reader, you want to structure these words, phrases, or clauses in a similar way. The likeness of form enables the reader to recognize more readily the likeness of content and function. Consider the following example:
- His least favourite household chores are vacuuming, dusting, and to sweep.
In the example above, the reader is presented with three verbs that the subject dislikes. However, the verbs are not presented to the reader uniformly. While the first two are the same, the third verb is presented as an infinitive. As a result, this is an example of faulty parallel structure. To correct this sentence and achieve parallel structure, the following edit could be made:
- His least favourite chores are vacuuming, dusting, and sweeping.
Now, each item in the list, in this case a verb, is presented to the reader in the same form.
In the example below, two phrases are presented to the reader in varying forms.
- Mary ran down the stairs, and the door is what she ran out of.
In this sentence, there are two prepositions tied to phrases: down is tied to the stairs, and out of is tied to the door. The single verb in the sentence, ran, pertains to both of these phrases; however, the phrases are not presented to the reader in the same way. To correct this error, down the stairs and out the door could be combined with the verb to make the sentence more uniform. For example:
- Mary ran down the stairs and out the door.
The chart below indicates examples of faulty parallel structure as well as corrections.
Faulty Parallel Structure
|She should walk the dog and doing her homework is a good idea.||She should walk the dog and do her homework.|
|Successful students are motivated, punctual, and they listen actively in class.||Successful students are motivated, punctual, and attentive.|
|Rita bought a stainless steel watch and a necklace made of white gold.||Rita bought a stainless steel watch and a white gold necklace.|
|Kittens are adorable because they are tiny and the fur they have is so fluffy.||Kittens are adorable because they are tiny and fluffy.|
Parallel structure is especially important to consider when drafting thesis statements for academic writing. If your thesis statement presents your reader with two or more, main points, you must ensure that each point is expressed in parallel form.
The example below is a thesis statement that is NOT in parallel form:
- Effective group work is a result of cooperation, communication, and being organized is good, too.
The first two items are presented in the same form, but the last breaks the pattern by introducing the item with a verb and including additional content (is good, too).
Consider the revision below:
- Effective group work is a result of cooperation, communication, and organization.
This revision presents each item in the same form. It is more concise and, therefore, more effective.