Parallelism is all about maintaining consistency among words, phrases, or clauses. Using parallel structure provides clarity and places equal emphasis on the ideas you’re putting forth. Today we’re going to look at how to maintain parallelism in three stages. First, we’ll explore parallelism using infinitive phrases and gerunds. Next, we’ll turn our attention to verb tenses. Finally, we’ll learn how to keep a series of clauses parallel.

Infinitive phrases and gerunds

Keeping multiple infinitive phrases parallel is relatively simple. All you need to remember is that the “to” must go before either the first verb or all the verbs.

Parallel:

Aimee likes to read, write, and draw

OR

Aimee likes to read, to write, and to draw.

Not parallel:

Aimee likes to read, write, and to draw.

Achieving parallelism in a list of gerunds is even easier than with infinites. Just make sure each item in your list ends with “ing.”

Mark enjoys singing, exercising, and sleeping.

Suzy dislikes studying, cleaning, and driving.

Take care that you don’t mix and match infinites and gerunds, or you’ll end up with something like this.

Ellen loves dancing, to knit, and baking.

You can fix this example of faulty parallelism by making all the items gerunds or infinities.

All gerunds:

Ellen loves dancing, knitting, and baking.

All infinites:

Ellen loves to dance, knit, and bake.

OR

Ellen loves to dance, to knit, and to bake.

Verb Tenses

Parallelism is not limited to just keeping infinites and gerunds separate. You must also keep verb tenses consistent throughout a sentence. Take a look at the next example.

The editor felt Jason was unreliable because he routinely misquoted sources, submits articles with punctuation errors, and missed deadlines.

The verb tenses in this sentence are inconsistent. “Misquoted” and “missed” are past tense, but “submits” is present tense. You can correct this by changing “submits” to “submitted.”

The editor felt Jason was unreliable because he routinely misquoted sources, submitted articles with punctuation errors, and missed deadlines.

You could also fix this sentence by changing past tense verbs to present tense. However, this takes more a lot more work because you must modify all the other verbs. If you don’t you’ll be creating a new parallelism error even as you fix the original one!

The editor feels Jason is unreliable because he routinely misquotes sources, submits articles with punctuation errors, and misses deadlines.

As you can see, you have to correct four verbs instead of one. This also shifts the sentence into the present tense, subtly changing its meaning.

Clauses

Finally, let’s expand our exploration of parallelism to include clauses. Maintaining parallelism with clauses requires using both the same verb form and the same basic grammatical structure for each clause in a sentence. Varying either of these will break the parallelism.

The teacher told Emily that she should review her class notes, that she should not study too long, and to sleep well before the test.

The first two clauses repeat the “she should” parallel structure, but the third clause switches to an infinitive phrase. There are two ways to fix this. You can either add “she should” to the beginning of the third clause, or you can omit “she should” from the second clause.

The teacher told Emily that she should review her class notes, that she should not study too long, and that she should get a good night’s sleep before the test.

OR

The teacher told Emily that she should review her class notes, not study too long, and get a good night’s sleep before the test.

While this is a more complicated sentence, it follows the same basic rule governing where “to” can go in parallel infinite phrases. “She should” can go before the first verb or before every verb, but you can’t switch back and forth.