“It was the best of times, it was the worst of times.”
“I came, I saw, I conquered.”
“Ask not what your country can do for you; ask what you can do for your country.”
Their parallel structure is one reason they’re memorable.
WHY SHOULD YOU CARE?
The human brain likes patterns, and using parallel structure makes your writing clearer and more memorable. It’s one characteristic that makes writing pleasing for the reader.
On the flip side, nonparallel sentences are jarring and confusing. Take the following example: The strawberries are on the counter, in the fridge and ice cream is in the freezer.
Huh? Where are the strawberries — on the counter or in the fridge? What’s in the fridge?
How to fix it: Clarify what’s in the fridge, so that each item’s location is clear and each part of the sentence has its own verb:
Option 1: The strawberries are on the counter, the blueberries are in the fridge and the ice cream is in the freezer.
Option 2: The strawberries are on the counter and in the fridge, and the ice cream is in the freezer.
Here are a couple more examples of faulty and correct parallelism:
NO: The laptop has a touch screen, 500GB of storage and costs just $349.
YES: The laptop has a touch screen, includes 500GB of storage and costs just $349.
YES: The laptop has a touch screen and 500GB of storage, and it costs just $349.
Why? Each element in the list needs a corresponding verb.
NO: The researchers asked the study participants five questions, and then they were told to recite a poem.
YES: The researchers asked the study participants to answer five questions and then told them to recite a poem.
Why? The first sentence mixes active voice with passive voice. Pick one or the other; active voice is much better. It also helps to clarify whether “they” refers to the researchers or the participants.