Parallel structure is as essential for good writing as it is for railroad tracks. Just as railroad tracks must be level and equally spaced to insure a safe ride, elements within a sentence that are alike in function should also be alike in construction. Failure to do so results in faulty parallelism.
Parallel construction or parallelism is necessary when a sentence contains similar elements. Every part of a parallel element must match the others in both function and grammar. This creates a symmetry, similar to railroad tracks, that insures a clear, smooth read.
Here are five constructions in which parallelism is required:
- Elements that are joined by coordinating conjunctions. These can be words, phrases or clauses. (Need a mnemonic to remember the conjunctions for, and, no, but, or, yet? Try FANBOY or Four Apes Nibbled Big Orange Yams.)
Faulty Parallelism: The train left the station and advancing to the next stop. (inconsistent verb tense)
Parallel Construction: The train left the station and advanced to the next stop. (consistent verb tense)
2. Items in a list or series.
Faulty Parallelism: The train, designed for function rather than comfort, had no passenger cars, no sleepers, and it didn’t have a dining car.
Parallel Construction: The train, designed for function rather than comfort, had no passenger cars, no sleepers, and no dining car.
Or: The train, designed for function rather than comfort, had neither passenger cars, sleepers, nor diners.
3. When comparing elements.
Faulty Parallelism: The Burlington Northern’s stock is newer than Amtrak.
Parallel Construction: The Burlington Northern’s stock is newer than Amtrak’s. (possessive indicates comparison of like objects: the stock belonging to the rail line, not the line itself.)
Faulty Parallelism: I like flying better than to take the train.
Parallel Construction: I like to fly better than to take the train.
4. Joining elements with a linking or to be verb.
Faulty Parallelism: Riding the rails is to take a step back in time.
Parallel Construction: Riding the rails is taking a step back in time.
5. Joining elements with a correlative conjunction. Correlative conjunctions are pairs of conjunctions (either-or; neither-nor; both-and; not only-but also) that require equal/parallel structures after each one.
Faulty Parallelism: The owner of the rail line didn’t communicate with the victims nor acknowledge their loss.
Parallel Construction: The owner of the rail line neither communicated with the victims nor acknowledged their loss.
May all your rails run straight and smooth.