Parallel structure is the arrangement of like ideas in grammatically consistent terms. Parallel structure appears in all sorts of series: nouns, verbs, adjectives, and adverbs. Our job as writers is to align those nonparallel expressions in parallel form.
Nonparallel Nouns: Anne will meet with the plant manager, the supervisor of line, and the person who does the pricing.
Parallel Nouns: Anne will meet with the plant manager, line supervisor, and cost estimator.
Nonparallel Verbs: Bill does field assessments, writes reports, presenting key findings during briefings.
Parallel Verbs: Bill assesses field conditions, writes reports, and presents key findings.
Nonparallel Adjectives: Carmen is conscientious, creative, and she collaborates well.
Parallel Adjectives: Carmen is conscientious, creative, and collaborative.
Nonparallel Adverbs: Dennis furnished the model with great speed, accurately, and he was thorough.
Parallel Adverbs: Dennis furnished the model quickly, accurately, and thoroughly.