Parallelism Frequently in writing and speaking, you need to indicate equality of ideas. To show this equality, you should employ parallel grammatical constructions. In other words, convey parallel thought in parallel language; conversely, use parallel language only when you are conveying parallel thoughts.

Coordinate Elements In employing parallelism, balance nouns against nouns, infinitives against infinitives, prepositional phrases against prepositional phrases, adjective clauses against adjective clauses, etc. Never make the mistake of saying “I have always liked swimming and to fish.”  Because the object of have liked is two parallel ideas, you should say: I have always liked swimming and fishing. (And joins two gerunds.) I have always liked to swim and to fish. (And joins two infinitives.)

Coordinate Elements Parallel prepositional phrases are illustrated in the following sentence. The parallel elements appear immediately after the double bar: GovernmentIIof the people, IIby the people, andIIfor the people shall not perish from the earth.

Coordinate Elements Parallel noun clauses He said II that he would remain in the East, II that his wife would travel in the Northwest, andII that his son would remain in the South. Parallel independent clauses II I came; II I saw; II I conquered.

Coordinate Elements Parallel elements are usually joined either by simple coordinating (FANBOYS) conjunctions or by correlative conjunctions (both...and; not only…but also). Whenever one of these connectives is used, you must be careful to see that the elements being joined are coordinate or parallel in construction:

Coordinate Elements FAULTY: Ann is a girl with executive ability and who therefore should be elected class president.  This sentence contains faulty parallelism, since and is used to join a phrase (with executive ability) and a dependent clause (who therefore should be elected class president). Ann is a girl II with executive ability and II who therefore should be elected class president.

Coordinate Elements CORRECT: Ann is a girl II who has executive ability and II who therefore should be elected class president.

Coordinate Elements A common error results from making a construction appear to be parallel when actually it is not:  FAULTY: Mr. Lee is honest, intelligent, and works hard. Mr. Lee is II honest II intelligent and II works hard.

Coordinate Elements  CORRECT: Mr. Lee is honest, intelligent, and industrious. Mr. Lee is II honest II intelligent and II industrious.

Correlative Conjunctions Remember that correlative conjunctions are used in pairs: either…or; neither…nor; both…and; not only…but also When these conjunctions are used in a sentence, they must be followed by parallel constructions.

Correlative Conjunctions INCORRECT: I hope either to spend my vacation in Mexico or Hawaii. I hope either II to spend my vacation in Mexico or II Hawaii. CORRECT: I hope to spend my vacation either in Mexico or in Hawaii. I hope to spend my vacation either II in Mexico or II in Hawaii.

Correlative Conjunctions INCORRECT: She knew not only what to say, but also she knew when to say it. CORRECT: She knew not only what to say, but also when to say it.

Repetition of Certain Words In order to make parallel constructions clear, you must sometimes repeat an article, a preposition, an auxiliary verb, the sign of the infinitive (to), or the introductory word of a dependent clause. Three of these types of necessary repetition are illustrated in the sentences that follow: OBSCURE: He must counsel all employees who participate in sports and also go on recruiting trips throughout the Southwest. CLEAR: He must counsel all employees who participate in sports and must also go on recruiting trips throughout the Southwest.

Repetition of Certain Words OBSCURE: The instructor wants to meet those students who enjoy barbershop harmony and organize several quartets. CLEAR: The instructor wants to meet those students who enjoy barbershop harmony and to organize several quartets. OBSCURE: He thought that economic conditions were improving and the company was planning to increase its dividend rate. CLEAR: He thought that economic conditions were improving and that the company was planning to increase its dividend rate.

Than and As When than and as introduce comparisons, you must be sure that the things compared are similar. Don’t compare, for instance, a janitor’s salary with a teacher. Compare a janitor’s salary with a teacher’s salary.  INCORRECT: A janitor’s salary is frequently more than a teacher.  CORRECT: A janitor’s salary is frequently more than a teacher’s.

Incorrect Omission of Necessary Words INCORRECT: I always have and always will remember to send my first-grade teacher a Christmas card. Remember is used correctly after will, but after have the form needed is remembered. Consequently, remember cannot serve as the understood participle after have. CORRECT: I always have remembered and always will remember to send my first-grade teacher a Christmas card.

Incorrect Omission of Necessary Words INCORRECT: He gave me an apple and pear. CORRECT: He gave me an apple and a pear. INCORRECT: I was interested and astounded by his story. CORRECT: I was interested in and astounded by his story. INCORRECT: She is as tall if not taller than her sister. CORRECT: She is as tall as, if not taller than, her sister.

Correct Use of “Unparallel” Constructions Parallelism is not always possible.  CORRECT THOUGH “UNPARALLEL”: He spoke slowly and with dignity.