Parallel structures include word or phrase patterns that are similar. When ideas in a sentence or paragraph are similar, you can reinforce these similarities in meaning through creating parallel structures. Effective parallelism creates symmetry in sentences and adds force to your writing; it emphasizes the likeness between two or more ideas.
The first sentence below contains parallel structures; the second does not.
The Writing Center needs tutors who are ambitious, who are self-motivated, and who are dedicated.
The Writing Center needs tutors who are ambitious, motivate themselves, and exhibit dedication.
In the first example, the words "who are" are repeated three times, forcing the words "ambitious," "self-motivated," and "dedicated" to be alike. In the second example, "who are" makes sense with "ambitious," but "are" must be dropped for a reader to make sense of the following phrases in the sentence. When sentences are truly parallel, and the verbs are used exactly the same in each phrase, they do not need to be repeated.
Repeating the verbs becomes a question of style and emphasis. Don't go too far with parallelism! Sentence 1 above could also be stated, without too much repetition:
The Writing Center needs tutors who are ambitious, self-motivated, and dedicated.
Janet researches cell membranes and walls.
Is Janet a biologist, or a biologist with an interest in interior design? This revision makes the meaning clear:
Janet researches cell membranes and cell walls.
Items in a series:
As an artist, he drew, painted, and sculpted. I came; I saw; I conquered. Eat, drink, and be merry.
The musicians began not only to sing, but also to dance. Ask not what your country can do for you; ask what you can do for your country. (John F. Kennedy)
White chickens lay white eggs, and brown chickens lay brown eggs; so if white cows give white milk, do brown cows give chocolate milk?
Lists and Outlines:
The research had three main goals: To discover the cause of the disease. To propose a medicinal treatment. To document the success of the treatment.
Note: As you write or update your resume, make sure all your listings
"Responsibilities included . . . ." as the beginning of each description, or begin each description with verbs in the same tense: "Researched," "Conducted," "Supervised," etc.