Parallelism and Faulty Comparisons

The Principle of Parallelism

Parallelism is a generally recognized principle of good writing: when you write a complex sentence, you should try to make the different parts of the sentence match each other in structure. There should be a structural consistency throughout the sentence. That consistency makes the sentence smoother, more natural, and easier to understand.

Parallelism with Correlative Conjunctions

A number of frequently used expressions, such as “not only…but also…” and “either…or…,” require a parallel construction. Be sure that you position these conjunctions carefully within the sentence:

Batman was sure he was going to not only look cooler than Aquadork but also Superman, who thought he was so fly that he could get away with going to prom in his Cheetos-stained uniform.

Whatever kind of word appears after the first conjunction should also appear after the second conjunction. Usually, it’s best to avoid repeating words unnecessarily. The words that precede the first conjunction are also understood to apply to whatever comes after the second conjunction, so they don’t have to be repeated:

Batman was sure he was going to look cooler than not only Aquadork but also Superman.

The distributive property in math says (to put it in terms easily comparable to grammar) that an element that precedes an expression in parentheses is multiplied by each element of that expression:

x(y + z) = xy + xz

The same rule applies to these kinds of parallel constructions:

look cooler than (not only Aquadork but also Superman) = look cooler than Aquadork and look cooler than Superman

This rule allows us to simplify the sentence and avoid highly repetitive wording.

Parallelism in Comparisons

You’ve probably heard the expression “apples and oranges,” which is used to suggest that two things are so different that it doesn’t make sense to compare them directly. In Standard English, the rules about making comparisons are quite strict; the wording of the sentence must suggest the comparison very precisely.

Batgirl, Aquadork’s back-up date, was jealous of Aquababe because Aquababe’s dress looked a lot hotter than Batgirl Batgirl’s dress.  (or just “than Batgirl’s”)

The sentence above is intended to express a comparison of one person’s dress with another person’s dress, but the wording is unparallel and thus illogical. (To compare one person’s dress to another person is figuratively like comparing an apple to an orange when you really mean to compare two apples.) This kind of inconsistency is called a faulty comparison.

Although Aquadork wanted to win Aquababe back, Batman’s dance moves were smoother than Aquadork Aquadork’s.

In more formal or complex comparisons, the pronouns that (for singular nouns) and those (for plural nouns) are used to avoid repetitive wording:

The dance moves that Batman busted out were smoother than the dance moves that Aquadork tried to do. (too repetitive)

The dance moves that Batman busted out were smoother than those that Aquadork tried to do.

In addition, make sure you use the idiomatically correct wording when expressing comparisons. Than is used for expressing differences using comparative adjectives (e.g. hotter) and the expression “as…as…” is used for expressing similarity. According to traditional grammar authorities, “so…as…” is the correct expression to use for negative comparisons of this kind (comparisons involving words such as no, not, and never). However, this rule is rarely taught or followed in contemporary English.

Batman looked just as hot than as Aquababe, and they made all of the other Superfriends look like chumps.

Batgirl’s nightly moontans just weren’t as so effective as Aquababe’s suntans.

Another kind of faulty comparison involves an error in logic. When comparing one thing to other things in the group it belongs to, be sure not to suggest a comparison of the thing to itself:

Robin (or “Batman’s Brat,” as Superman liked to call him) was dorkier than any of the Superfriends, and after his infamous “Bieber incident” at the prom, Superman argued that his membership should be revoked.

Since Robin is one of the Superfriends (at least for now), if you say that he is “dorkier than any of the Superfriends” you’re logically implying that he is dorkier than himself.  The solution to this problem is simple:

Robin was dorkier than any of the other Superfriends.

Now Robin himself is excluded from the group he is being compared to, and the comparison is logical.