Use parallel structure in your writing

Parallel structure arranges words, phrases, clauses, or sentences in a series of two or more grammatically equivalent structures.

The following sentences demonstrate the value of parallelism in making meaning clear. Although both sentences are grammatically coherent, the patterning of the second (indicated by italics) makes the meaning easier to grasp.

Parallelism achieved by beginning each item in the series with a verb.

  • The trees are magnificent—twisted by winds, hammered by storms, and snows bent them.
  • The trees are magnificent—twisted by winds, hammered by storms, and bent by snows. 

Parallelism achieved by each clause beginning with a noun.

  • The law serves a double purpose; first, it protects the people, and second, the capture of criminals.
  • The law serves a double purpose; first, the protection of people, and second, the capture of criminals.

Lack of parallel structure often shows up in lists.
Notice how beginning each item in the list with the same grammatical structure makes it quicker to read and to understand.

  • The Ways and Means Committee wanted the following information:
    • The names of all personnel.
    • What are the types of positions in the field offices?
    • The rate of turnover for the past five years.
    • They also wanted to know what our recruiting plans are for the next fiscal year.
  • The Ways and Means Committee wanted the following information:
    • The names of all personnel.
    • The types of positions in the field offices. (Or, The types of field office positions.)
    • The rate of turnover for the past five years.
    • Our recruiting plans for the next fiscal year.

Although the last item in this list does not begin with “the” and includes an adjective, it remains parallel to the others because it begins with a noun.