When you list two or more things in a sequence, they must be in EXACTLY the same grammatical format, or they are NOT PARALLEL.
Wrong: I took the job for the extra money and to increase my status.
If you’re listing even two things in a sentence, they need to be identically formatted.
Correct: I took the job for the extra money and for the improved status
Important Rule: When you’re listing things out or comparing them, make sure the verbiage used to describe them is as repetitive as possible.
Wrong: I like Melissa because she seems so sweet and for her beautiful eyes.
Correct: I like Melissa because she seems so sweet and because she has such beautiful eyes.
To complete the music program, a student must present one vocal performance, one instrumental performance, and composing one original work.
A. NO CHANGE
B. and one original composition
C. with one original composition
D. and to compose one original work
Solution: The phrase “and composing one original work” is one of three things that a student must present to complete the music program. We want the last item in the list to match the other two items as closely as possible. The answer is B. The phrase “and one original composition” matches the construction.
Another Rule: When making lists of any kind (pretty much any time you use the word ‘and’), try to make your sentences as parallel as possible.
Wrong: I like you because you’re a great guy and good at pool.
Correct: I like you because you’re a great guy and because you’re good at pool.
If this sounds unnatural, it’s because people rarely speak like this anymore. But, it is grammatically correct.
Changes in wind circulation, runoff from sewage, and they accumulate chemical fertilizers can lead to the creation of ocean waters low in oxygen and inhospitable to marine life.
A. NO CHANGE
B. Changing wind circulation, runoff from sewage, and accumulating chemical fertilizers
C. Changing wind circulation, having runoff from sewage, and to accumulate chemical fertilizers
D. Changes in wind circulation patterns, runoff from sewage, and accumulation of chemical fertilizers
Solution: D is the only answer that contains three nouns. The other options contain various combinations of nouns, verbs, and gerunds and are therefore not parallel.
Example 3 & 4
It was like standing on a bridge that must be crossed, leaving behind the carefree days of youth and  stepped into a life of responsibilities, business meetings, and  paying bills.
A. NO CHANGE
B. to step
D. we stepped
A. NO CHANGE
B. bills that have to be paid.
C. having to pay bills.
3. The word ‘and’ is the clue that acts like a parallel marker. The phrase “leaving behind the carefree days of youth” needs to be parallel with “stepped into a life.” Therefore, stepped should be changed to stepping. The correct answer is C.
4. “Responsibilities” and “business meetings” are nouns, which means the correct answer will also be a noun bills. The correct answer is D.
Parallel Structure with Multiple Sentences
So far, we’ve looked at parallel structure within a single sentence. The ACT, however, may also test your ability to recognize and create parallel structure when more than one sentence is involved. Although these questions may initially seem very complicated, they can actually be relatively simple to answer if you know what information to focus on.
An actor stands on the stage and delivers a monologue as an audience hangs onto his every word. A singer performs a ballad as listeners fall silent. As a group of spectators watch in awe, dancers glide across the stage.
Which choice best maintains the sentence pattern already established in the paragraph?
A. NO CHANGE
B. Watched by a group of spectators, dancers glide across the stage.
C. Gliding across the stage, dancers are watched by a group of spectators.
D. Dancers glide gracefully across the stage as spectators watch in awe.
Solution: Remember that the question is asking us to look at the pattern already established in the paragraph. That means we’re going to look at the preceding sentences before we consider the underlined sentence. Let’s start by considering just the beginning the first two sentences:
Sentence #1: An actor...
Sentence #2: A singer...
Each of those sentences begins with a noun. That means the third sentence must start with a noun as well. Only option D places a noun right at the beginning of the sentence, so D is the correct answer.
How do we know that parts of a sentence need to be parallel to each other? Often, we can use Parallel Markers - words that link or contrast items and that force those items to be parallel.
Wrong: The college experience is not only an exciting time to meet new people and also a stressful one because of the level of independence required.
Correct: The college experience is not only an exciting time to meet new people but also a stressful one because of the level of independence required.
Pair errors like the one above are freebies on the ACT as long as you remember to check for them.
As covered earlier in this chapter, just remember that whenever you have a paired construction, the two things being paired should be as parallel as possible Parallel Elements.
James Barrie, the author of Peter Pan and other plays, is noted for portraying adulthood as unpleasant and childhood is glorified.
A. NO CHANGE
B. childhood is being glorious
C. childhood as glorious
D. childhood glorified
Solution: James Barrie is noted for portraying two things. The two things are connected by the conjunction “and.” The first thing he is noted for portraying is “adulthood as unpleasant.” Its construction is NOUN + “AS” + ADJECTIVE. The construction of the second phrase should mirror. The phrase “childhood as glorious” matches the construction and fixes the error in parallel structure. The answer is C.
Comparisons are a form of parallelism that deserves special attention. As the name indicates, comparisons compare two parts of the sentence.
To spot comparisons, you must first learn certain signal words or phrases. Once you find a comparison, identify the two parts of the sentence that are being compared to each other.
The most important comparison signals are Like, Unlike, As, and Than. Whenever you see one of these four words, stop and find the two items being compared. Other common comparison signals are listed below:
- More than
- Less than
- Faster than
- Different from
- In contrast to/with
- As<word> as</word>
- As much as
- As little as
- As fast as
- The same as
Two general types of comparison errors can arise:
1. Terms Being Compared Must Be the Same
When directly comparing two terms, those terms need to be parallel to each other. Comparisons have to be parallel. That is, they must compare similar things.
Wrong: Frank’s build, LIKE his brother, is broad and muscular.
What two things are being compared? As written, the sentence is comparing Frank’s build directly to his brother, not his brother’s build. This is not a logical comparison. In order to correct this error, we need to change the comparison.
Correct: Frank’s build, LIKE his brother’s, is broad and muscular.
Let’s look at a harder EXAMPLE: Beethoven’s music, which broke a number of established rules with its structure and melodic form, is considered more revolutionary than Bach.
First, let’s find the comparison signal: MORE revolutionary THAN....
Now we look for the two things being compared. It is often easier to find the second thing, which follows the comparison signal: More revolutionary than Bach. So, what is more revolutionary than Bach?
The subject of the sentence: Beethoven’s music. This comparison is not parallel.
Correct: Beethoven’s music, which broke a number of established rules with its structure and melodic form, is considered MORE revolutionary THAN BACH’S.
Note again that we do not have to repeat the word music, as long as we have written Bach’s.
One reason that an insect can walk on walls while a human cannot is that the mass of its tiny body is far lower than humans.
A. NO CHANGE
B. far lower than that of a human’s body
C. lower by far than humans
D. far lower than is a human’s body
Solution: The sentence is comparing “the mass of its tiny body” with “humans.” This is an illogical comparison – the comparison should be between the mass of an insect and the mass of a human. We can eliminate option A.
Answer choice C contains the same error: it merely tweaks the word order. Answer D seems to fix the problem by adding “body,” but it’s still not correct to compare a human body with the mass of an insect body. The only answer that’s left is B, which correctly compares “the mass of its tiny body” and the mass of a human’s body. B is the right answer.
Many people struggle to learn to type, but shouldn’t get discouraged if they find the process to be more difficult than anticipated. It is a more difficult task to learn to type than mastering a simple word-processing program.
A. NO CHANGE
B. It is a more difficult task to learn to type than to mastering a simple word-processing program.
C. To master a simple word-processing program is a more difficult task than to learn to type.
D. Learning to type is a more difficult task than mastering a simple word-processing program.
Solutions: This sentence is comparing “to learn to type” with “mastering a simple word processing program.” These two terms need to be the same part of speech. We either need to change “mastering” to “to master” or “to learn” to “learning” so that parallel structure is maintained. The only answer choice that does that without introducing other errors is option D; B uses the ungrammatical “to mastering” and choice C inverts the logic of the sentence, claiming that mastering the word-processing program is the more difficult task. D is the correct answer.
2. Comparisons with Possessive Nouns and Pronouns
This type of error appears when possessive nouns or phrases (e.g. “the _ of _”) are in play.
Wrong: Which is larger, the population of New York or Los Angeles?
This sentence compares “the population of New York” with the entire city “Los Angeles.” We can fix this error by adding “the population of” before “Los Angeles,” or revising the sentence so that the information specifying population size appears before the comparison.
Correct: Which is larger, the population of New York or that of Los Angeles?
Correct: Which is larger, the population of New York or the population of Los Angeles?
Let’s try a more complex EXAMPLE:
Wrong: Wandering around the furniture store, she decided that while burgundy and taupe would work well in her living room, the bright aquamarine lampshade would probably hog the spotlight.
This complex comparison involves the colors “burgundy” and “taupe” and “the bright aquamarine lampshade,” a tangible item. To fix this sentence, we need to either adjust “the bright aquamarine lampshade” to refer to just a color (e.g. “bright aquamarine”) or change “burgundy” and “taupe” so that they specify tangible items (e.g. “the burgundy drapes” & “the taupe carpet”).
Correct: Wandering around the furniture store, she decided that while burgundy and taupe would work well in her living room, bright aquamarine would probably hog the spotlight.