PARALLEL STRUCTURE
Parallelism in writing means that similar parts in a sentence are balanced by having the same structure.
Put nouns with nouns, verbs with verbs and phrases with phrases.
WRONG: I like math more than studying English.
(Noun and a Phrase)
RIGHT: I like math more than English.
WRONG: On vacation we swam, snorkled, and were eating at great restaurants.
(Simple Past Tense and Past Progressive Tense)
RIGHT: On vacation, we swam, snorkled and ate at great restaurants.
WRONG: Last night we went to a movie and dancing at a club.
(Prepositional Phrase and Gerund (-ing) Phrase)
RIGHT: Last night we went to a movie and to a dance club.
WRONG: Your new training program was stimulating and a challenge.
(Adjective and Noun)
RIGHT: Your new training program was stimulating and challenging.
WRONG: The sales representatives have started using the new techniques and to produce higher sales.
(Gerund Phrase and Prepositional Phrase)
RIGHT: The sales representatives have started using the new techniques and producing higher sales.
WRONG: This scanner is easy to operate, efficient, and it is relatively inexpensive.
(Two Adjectives and a Clause)
RIGHT: This scanner is easy to operate, efficient and relatively inexpensive.