GMAT Sentence Correction: Where Do I Start?

by , Jul 31, 2014

On some Sentence Correction (SC) problems, an error jumps out at you immediately. On others, youre left trying to figure out where to start. How do you dig in when the starting point isnt obvious?

Try this GMATPrep problem from the free exams and then well talk about it.

* A recording system was so secretly installed and operated in the Kennedy Oval Office that even Theodore C. Sorensen, the White House counsel, did not know it existed.

(A) A recording system was so secretly installed and operated in the Kennedy Oval Office that

(B) So secret was a recording system installation and operation in the Kennedy Oval Office

(C) It was so secret that a recording system was installed and operated in the Kennedy Oval Office

(D) A recording system that was so secretly installed and operated in the Kennedy Oval Office

(E) Installed and operated so secretly in the Kennedy Oval Office was a recording system that

The first step on SC is to glance at the start of the underline (even before you read the sentence) in order to see whether the opening change in the answers gives you a clue about where to start. In this case, the underline starts right at the beginning of the sentence. A scan down the beginning of each answer choice signals exactly nothing on this problem. Now what?

Okay, on to step 2: read the original sentence (for both meaning and grammar). What do you think?

The sentence sounds kind of clunky. It uses an idiom (so X that Y). Is the idiom used correctly? Here are some correct examples.

She was SO extraordinarily lucky THAT she actually won the lottery three separate times.

The CEO was SO preoccupied with profits THAT he missed the signs of a market collapse.

Notice the structure in these examples. There are actually two subject-and-verb pairsone set before the word that and one set after. In addition, the Y portion of the sentence (after that) represents evidence to support the scenario in X or some consequence of that scenario. The fact that she won the lottery three times is evidence that shes really lucky. The CEOs preoccupation actually caused the CEO to miss signs of the collapse.

The original sentence has this same structure:

(A) The system was SO secretly installed THAT even Sorensen did not know it existed.

This structure, then, is correct in the original sentence. What about the other answers?

Heres where things start to get messy! Strip down the structures for each choice:

(B) SO secret was the system (even Sorensen did not know it existed.)

(C) It was SO secret THAT a system was installed (even Sorensen did not know it existed.)

(D) A system that was SO secretly installed (even Sorensen did not know it existed.)

(E) Installed SO secretly was a system THAT (even Sorensen did not know it existed.)

Answer (B) is missing the that portion of the idiom. People often skip this word in real life but notice what happens when you do so:

She was so late, I wasnt even sure she was coming!

There are two complete sentences connected only by a comma. Thats a comma splice error! Eliminate (B).

Answer (D) does have the word that, but its before the so. This sentence turns out to have no main verb for the subject (system). That was so secretly installed modifies system, and even Sorensen doesnt provide a verb for system. Eliminate (D).

In both cases, the missing that signaled a problem with sentence structure.

Answer (C) has the that but wait a second. It moved. Is it still okay?

No! That a system was installed is just a modifier of secret; its not actually finishing off the idiom by providing some follow-on info or consequence of the so portion. There should still be a that before even Sorensen:

It was SO secret that a system was installed THAT even Sorensen did not know it existed.

(That sentence may still sound clunky to you. The double thatmay be tripping your sounds bad! instincts, or possibly the passive It was opening. I definitelywouldnt write the sentence this way myself!)

Eliminate (C). Okay, what about answer (E)?

The so X portion of the sentence should provide the opening information that is later addressed in the that Y portion. What was so surprising that Sorensen didnt know?

The surprise was that this system had been installed and was being operated inthe area where he worked. In answer (E), though, those verbs come before the sothat is, they are not part of the X portion of the sentence. Eliminate (E).

Only answer (A) uses the idiom to convey the proper meaning: This system was SO secretly installed and operated THAT even someone who worked there didnt know about it!

The correct answer is (A).

Key Takeaways: Meaning, Structure, and Idioms in SC

(1)When you dont spot an obvious way into the sentence, consider examining the core sentence, particularly if the sentence contains a structure that extends across nearly the whole thing, such as parallelism or an idiom (as in this case).

(2) Messing up an idiom can lead to both meaning and structure errors. Even if you dont know the idiom, then, you might still be able to narrow down the answers! In the problem above, answer (B) was a run-on and answer (D) was a fragment, all because the usage of the idiom was messed up.

(3) Stripping the sentence down to the minimum necessary to test the sentence (and idiom) structure takes some time but may be your best shot at answering the question. This may not get you all the way to the right answer, but theres a good chance it will help you eliminate some wrong answers.

* GMATPrep questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.