Parallelism — Match the Pattern

Items in a list or comparison must follow the same grammatical structure.

Wrong: "She likes running, to swim, and biking."

Right: "She likes running, swimming, and biking."

Wrong: "The coach told them to practice daily, that they should eat well, and sleeping enough."

Right: "The coach told them to practice daily, eat well, and sleep enough."

Parallel comparisons:

Wrong: "The population of Tokyo is greater than New York." (compares population to a city)

Right: "The population of Tokyo is greater than that of New York."

Strategy: Any time you see a list, "and," "or," "not only...but also," or "both...and" — check that every item matches in form.

Reference:

Wikipedia: Parallelism

https://en.wikipedia.org/wiki/Parallelism_(grammar)