Faulty parallelism: what it is and how to fix it

One of the most common grammatical errors I see on the web is faulty parallelism. I assume most writers are not even aware of the error. Faulty parallelism exists when two potentially related actions differ in structure.

Let me illustrate.

I enjoy reading books, going for walks, and photography.

In this sentence, we read three items the subject enjoys.

• Reading books
• Going for walks
• Photography

You probably noticed the difference between the first two and the last one, the last one being a noun and the others being specific actions.

To make this a better sentence, we would structure all three hobbies similarly. Here is one way we could be rewrite this sentence.

I enjoy reading books, going for walks, and taking photographs.

This idea does not apply to just lists, however.

Jon not only cancelled the meeting, but also he was skipping out on work.

Here, the correlative conjunction of “not only . . . but also” requires parallel forms for the thoughts it joins. The first thought uses the simple past tense while the second thought uses the past progressive tense. Since we use the past progressive tense to describe events that were just about to occur when a new event happened, we should rewrite the sentence as follows:

Jon not only cancelled the meeting, but also he skipped out on work.

If the past progressive tense is important to keep, you could also rewrite it without the correlative conjunction.

Jon was planning to skip out of work when he cancelled the meeting.

Of all the common grammatical errors, faulty parallelism is probably one of the easiest to correct.