Fix Parallel Sentence Structure Mistakes in Writing

A common writing issue for many authors of essays and research papers is making sure to use parallel structure. In many ways, the English language operates like math. When we string words or phrases together, we must make sure that all parts are of “equal value.” That is, they must all be in the same form.

What is parallelism and why is it a problem in writing?

Identifying parallel sentence structures in any writing can be difficult. So let’s start by looking at a few examples.

1. I like apples, oranges, and going to the zoo.
2. The coach advised that I should eat healthily, exercise regularly, and that joining a gym would make this easier.
3. Mary is a celebrated author, dancer, and writes great songs.

Did you notice any problems with the above sentences? If not, don’t worry. After reading this article, you’ll become an expert at spotting parallelism issues!

Let’s take another look at the sentences written above. This time, examine the colored words and phrases below. The underlined portions indicate the parts of the sentence that serve as the triggers for parallel structures.

1. I like apples, oranges, and going to the zoo.
2. The coach advised that I should eat healthily, exercise regularly, and that joining a gym would make this easier.
3. Mary is a celebrated author, dancer, and writes great songs.

Why are the red parts above incorrect?

• Sentence 1 says, “I like noun, noun, and -ing phrase.”
• Sentence 2 says, “The coach advised that I should: (1) verb; (2) verb; (3) that -ing phrase.
• Sentence 3 says, “Mary is a noun, noun, and verb.”

These three sentences break parallel structure. Each of the red words in the examples above is in a different grammatical form than the other words in their respective lists.

How do we fix this problem?

There are three ways to fix a parallel structure problem. In each case, the idea is to make all the parts match in grammatical form. We’ll use the sample sentences from above to illustrate each method.

Method #1: Make the grammatically nonconforming part match the other parts.

This method is often the simplest way when you’re dealing with nonparallel words or simple phrases. Accordingly, we recommend method #1 for most cases involving parallelism issues. However, with complex phrases or clauses, you might lose some meaning, so we recommend method #3 (below) for those situations.

Method #2: Make the other parts match the grammatically nonparallel part.

Be careful when using this method. Changing the previous parts might create repetitive phrasing (like in example 1 below), in which case, we recommend changing the nonparallel part rather than the rest of the sentence! This method will also not solve the problem of lost meaning in more complicated sentences.

Method #3: SPLIT the sentence.

Sometimes, changing a part of a sentence might require substantial restructuring, otherwise, you might accidentally change the original sentence’s meaning. In those cases, we recommend creating multiple sentences.

Watch out for tricky comparative phrases!

Most simple sentence styles that use parallel structures are connected by conjunctions like “and,” “or,” or “but.” However, there are some tricky constructions that often plague many writers: parallelism in modifying clauses (e.g., relative clauses, and participial clauses) and comparative phrases (e.g., correlative conjunctions). Watch out for tricky comparative phrases!

• Relative clauses use “that” or “which.”
• Participial clauses are phrases that are made from verbs and are used like adjectives. For example, “This car is built to last.”
• Correlative conjunctions include terms like “not only…but also,” “either…or,” “neither…nor,” “if…then,” etc.
• Comparison structures include the typical “than” or “as.”

All these types of expressions require parallel grammatical forms!

When correcting these kinds of statements, treat the comparative phrases or the second half of the correlative conjunction like equal signs and ask yourself: “Do I have the same grammar structure on both sides?”

Another whammy: watch verb tenses!

Another parallel structure we struggle with is verb tense shifting! Raise your hand if you have ever said something like the following:

1. “I really like this movie, which was why I bought it.”
2. We knew that we had little time, work had to be finished, and we needed to hurry.

Raises hand What’s wrong, you ask? Let’s look again:

1. “I really like this movie, which was why I bought it.”
2. We knew that we had little time, work had to be finished, and we needed to hurry.

Sentence 1 above switches from the present tense to the past tense, while sentence two throws in a passive voice structure in the middle of the list of “that” clauses. Don’t do it!  What would they look like if corrected?

1. “I really like this movie, which is why I bought it.”
2. We knew that we had little time, we had to finish the work, and we needed to hurry.

Parallelism Checklist

1. Identify any conjunctions or lists in your sentence.
2. Look at the structure of your words and phrases on either side of those conjunctions. Do you have nouns, verbs, adjectives, -ing phrases, etc. on both sides?
3. Look at the clauses you have in a sentence. Do you have the same kind of clauses in your lists? Do you have the same type of descriptive clause describing the same thing?
4. Are your verbs in the same tense on both sides of a conjunction and within your modifying clauses?
5. If you have a list, does each part of the list (A, B, C, etc.) have the same grammatical form?

We hope these tips have taught you how to stop issues with parallelism in your writing. Now you are ready to go forth and write your essay or paper with confidence.

And if you are still a bit unsure about whether your writing is free of errors, we recommend using our English editing and proofreading services to polish your writing to perfection. Our academic editing and paper editing services match your work to professional editors with expertise in your paper’s subject area.