Parallelism

Conjoined items in a sentence must be in the same grammatical form.

Incorrect: I like to jog and walking.

In the above sentence, to jog and walking are not parallel in grammatical construction.

Parallelism is the matching of the forms of words, phrases, or clauses within a sentence. Editing your work for parallel construction improves clarity and emphasizes your points.

Rule to Remember

Conjoined items in a sentence must be in the same grammatical form, i.e. grammatically parallel.

Correcting Faulty Parallelism

To avoid faulty parallelism, the sentence above should be corrected to:

Correct: I like jogging and walking.

Words, phrases, and clauses joined by a coordinating conjunction (and, but, or, nor, for, so, yet) need to have parallel grammatical construction.

Incorrect: We all need good nutrition and to exercise on a regular basis.
Correct: We all need good nutrition and regular exercise.

Words, phrases, and clauses joined by a correlative conjunction (not only... but also, both... and, either... or, neither... nor) need to have parallel grammatical construction.

Incorrect: like both to read books and watching movies.
Correct: like both to read books and to watch movies.

Words, phrases, and clauses joined by a comparative expression (as much as, more than, less than) need to have parallel grammatical construction.

Incorrect: enjoy going out to a movie as much as I like to rent a movie and stay home to watch it.
Correct: enjoy going out to a movie as much as I enjoy renting a movie and staying home to watch it.

Rule to Remember

Items joined by a coordinating or a correlative conjunction, or by a comparative expression need to be parallel in their grammatical form.

In the following example, inserting because before each of the elements makes each point a subordinate adverbial clause and adds to the clarity of the whole sentence.

Incorrect: Many people maintain a healthy diet because they want to look healthy, it increases their energy, and they want to live longer.
Correct: Many people maintain a healthy diet because they want to look healthy, because it increases their energy, and because they want to live longer.

Words, phrases, and clauses in a series should be parallel in grammatical construction.

Incorrect: He is smart, honest, and has a great sense of responsibility.
Correct: He is smart, honest, and very responsible.

Items in a bulleted list should also be parallel in their grammatical form. For example,

Incorrect:    Set up your own wiki:
  • Explore sample wiki sites
  • Creating an account on free hosting services
  • Selecting a wiki name
  • How to choose privacy options
  • Creating and customizing your wiki site
Correct:    Set up your own wiki:
  • Explore sample wiki sites
  • Create an account on free hosting services
  • Select a wiki name
  • Choose privacy options
  • Create and customize your wiki site

Take Quiz