Many GMAT Sentence Correction problems involve the use of word pairs known as correlative conjunctions. These words are used to express a correlative relationship between two elements of a sentence. Here are the most commonly-used pairs:

either/or

neither/nor

both/and

not only/but also

not/but

GMAT Sentence Correction: Correlative Conjunctions

Correctly structuring a sentence around one of these pairs can be rather tricky, but there is a rule to help cut through the confusion. Let’s use an Official Guide problem with the not/but pair as an example.

GMAT Official Sentence Correction Problem

In her presentation, the head of the Better Business Bureau emphasized that companies should think of the cost of conventions and other similar gatherings as not an expense, but as an investment in networking that will pay dividends.

(A) as not an expense, but as

(B) as not expense but

(C) not an expense, rather

(D) not as an expense, but as

(E) not in terms of expense, but

Here’s the rule: imagine the correlative conjunctions as creating a “split” in the sentence. Everything between the two correlative conjunctions is one “branch,” and everything after the second correlative conjunction is the other “branch.” The branches should be parallel, and each one, when attached to the rest of the sentence, should form a complete idea with no redundancies. For this sentence, here are our branches:

an expense

as an investment in networking that will pay dividends.

Already we can see a problem. The second branch begins with the word “as,” while the first branch doesn’t. So the two branches are not quite parallel. But when we try attaching each of these branches to the rest of the sentence, we’ll see an even bigger problem.

                                                                        an expense

. . . companies should think of the cost . . . as

                                                                        as an investment . . .

The word “as” is used both in the “trunk” of the sentence and in the second branch, so it creates a redundancy. The correct answer choice is D. Here’s what it looks like when we apply the rule:

                                                                     as an expense

. . . companies should think of the cost . . .

                                                                    as an investment . . .

That’s better. Let’s try one with the not only/but also pair.

GMAT Official Sentence Correction Problem

Thomas Mann’s novel Doctor Faustus offers an examination not only of how difficult it is to reconcile reason, will, and passion together in any art form, but also a skillfully navigated exploration of the major concerns of modernism.

(A) an examination not only of how difficult it is to reconcile reason, will, and passion together in any art form, but

(B) an examination not only about the difficulty of reconciling reason, will, and passion in any art form, and

(C) not only an examination of how difficult it is to reconcile reason, will and passion in any art form, and

(D) not only an examination about the difficulty with reconciling reason, will, and passion together in any art form, but

(E) not only an examination of the difficulty of reconciling reason, will, and passion in any art form, but

Let’s create the “tree” from the given sentence:

                                                                  of how difficult it is . . .

. . . Doctor Faustus offers an examination

                                                                 a skillfully navigated exploration . . .

The placement of “not only” after “an examination” creates a sentence that correlates two things being examined in Doctor Faustus. But that’s not what the writer really wants to do. This sentence is meant to say that Doctor Faustus is not only an examination but also a skillfully navigated exploration. We can throw out answer choices A and B.

We can also throw out C because it ends with “and.” This would create the pair not only/and also, which is incorrect. D uses the wrong prepositions. We don’t say “an examination about” or “the difficulty with reconciling.” We say “an examination of” and “the difficulty of reconciling.” E is the correct answer.

 

GMAT Official Sentence Correction Problem

Many of the earliest known images of Hindu deities in India date from the time of the Kushan Empire, fashioned either from the spotted sandstone of Mathura or Gandharan grey schist.

(A) Empire, fashioned either from the spotted sandstone of Mathura or

(B) Empire, fashioned from either the spotted sandstone of Mathura or from

(C) Empire, either fashioned from the spotted sandstone of Mathura or

(D) Empire and either fashioned from the spotted sandstone of Mathura or from

(E) Empire and were fashioned either from the spotted sandstone of Mathura or from

Here’s the tree from the given sentence

                    from the spotted sandstone of Mathura

fashioned

                  Gandharan grey schist.

We need another “from” in front of “Gandharan grey schist”! There’s also a clarity problem with this entire “fashioned” modifier. Of course we know that the images, not the Kushan Empire, were fashioned, but the grammar in the sentence needs to make this abundantly clear.

Choice B gives us the “from” we need before “Gandharan grey schist,” but it also adds another “from” before the split, creating a redundancy.

Choices C and D move “either” before “fashioned,” but this doesn’t make sense. Fashioned needs to stay before the split, because we’re only correlating the materials from which the images were fashioned, not the event of their being fashioned. The correct answer is E. 

GMAT Official Sentence Correction Problem

Here’s one more question featuring the both/and pair:

While Noble Sissle may be best known for his collaboration with Eubie Blake, as both a vaudeville performer and as a lyricist for songs and Broadway musicals, also enjoying an independent career as a singer with such groups as Hahn’s Jubilee Singers.

(A) and as a lyricist for songs and Broadway musicals, also enjoying

(B) and writing lyrics for songs and Broadway musicals, also enjoying

(C) and a lyricist for songs and Broadway musicals, he also enjoyed

(D) as well as writing lyrics for songs and Broadway musicals, he also enjoyed

(E) as well as a lyricist for songs and Broadway musicals, he also enjoyed

This question can be answered quickly because the underlined portion doesn’t touch the first branch. We know that we need something to correlate with “both a vaudeville performer.” So we want our answer choice to begin with “and a lyricist,” not “and as a lyricist” like in the given version. Answer choice C is the only option!

Choices B opts for the phrase “writing lyrics,” which doesn’t parallel “vaudeville performer.” Choices D and E try to use the pair “both/as well as,” which is incorrect. It’s both/and. There’s also a verb form issue.

To make this sentence complete, we need “enjoyed,” not “enjoying.” But if you’re skilled with your correlative conjunctions, you need look no further than the beginning of choice C to answer this question.

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Contributor: Elijah Mize (Apex GMAT Instructor)