Parallelism

Parallelism in writing means that similar parts in a sentence are balanced by having the same structure. When making comparisons or listing items in a series, put nouns with nouns, verbs with verbs, and phrases with phrases.

NOT PARALLEL I like math more than studying English. [Math is a noun, but studying English is a phrase.]
PARALLEL I like math more than English.
NOT PARALLEL In class, we read, worked in groups, and were writing an essay. [Verbs must be in the same tense to be parallel.]
PARALLEL In class, we read, worked in groups, and wrote an essay.
NOT PARALLEL Last night we went to a movie and dancing at a club. [To a movie and dancing at a club are both phrases, but they have different forms. To a movie should be paired with another prepositional phrase: to a dance club.]
PARALLEL Last night we went to a movie and to a dance club.

When a sentence uses certain paired words called correlative conjunctions, the items joined by these paired words must be parallel. Correlative conjunctions, shown below, link two equal elements and show the relationship between them.

both . . . and neither . . . nor rather . . . than
either . . . or not only . . . but also
NOT PARALLEL Brianna dislikes both fruit and eating vegetables.
PARALLEL Brianna dislikes both fruit and vegetables.
NOT PARALLEL She would rather eat popcorn every night than to cook.
PARALLEL She would rather eat popcorn every night than cook.