GMAT Prep – Secrets to Sentence Correction

The Sentence Correction section in the GMAT ask you to choose the correct grammatical format of a sentence. Generally there are 7 categories of mistakes that the GMAT tends to test:

Wrong Words

The GMAT will give you a word that is similar in meaning to the one that you are supposed to use but slightly different. The incorrect words are not suitable substitutes for each other.

Example: Affect vs. Effect

Affect is most commonly used as a verb, while effect is used as a noun:

It’s hard to say how the price of gasoline will affect the economy in the long run.

It’s hard to say what effect the rising price of gasoline will have on the world economy.

Ambiguous Pronouns

Pronouns help make sentences less repetitive; when using pronouns the reader must be able to identify what noun the pronoun is referring to.

Example: Peter arrived 10 minutes before John to the party. He said he had to stop by the store to pick up some drinks.

In this example it isn’t clear if Peter or John stopped by the store to pick up the drinks.

If you come across a pronoun:

• check backwards through the sentence until you come across the noun that is being referred to
• ensure that you have the correct pronoun gender (he, she)
• ensure you have the right number (singular or plural)

Clause Modifiers should be close to what they modify

The woman saw the bird on the hill with binoculars.

What exactly does that sentence mean? It could mean that a woman is looking through binoculars up at a bird on a hill, or the woman is looking at a bird and binoculars which is on a hill, or the woman could be on the hill with the binoculars looking at the bird.

We have two modifiers here, which are phrases that give additional information: on the hill and with the binoculars. It isn’t clear from the way in which the sentence has been corrected to what these modifiers refer. We can reasonably assume that the seeing was done with the binoculars, since that is what binoculars are for. However, it would have been better to put the modifier with the binoculars next to the seeing, and the on the hill next to the bird:

Using the binoculars, the woman saw the bird on the hill.

Parallelism Errors

Parallelism is the comparing or listing of two or more phrases or clauses which should both/all take the same form. Here is an example of two parallel items being compared:

Seeing is believing.

In this case, seeing is being listed alongside believing. They both take the same form, i.e. a verb ending in “-ing” which is being used as a noun (termed a gerund in grammatical text books). The three-word proverb above does not contain any parallelism errors. We could also rewrite the proverb as follows:

To see is to believe.

This time, both verbs are listed as infinitives, “to …” Again, since they are both in the same form, there is no parallelism errors. However, if we wrote the following:

To see is believing.

Here a gerund is being compared to an infinitive. This is grammatically wrong. The same applies to the following:

Seeing is to believe.

Redundant words

Can a sentence be written in a more succinct way without sacrificing grammatical correctness and meaning? Very often answer choices are wordier than necessary – this isn’t a grammatical error, merely a stylistic one, but sentence correction questions are not just about grammar. Style is also particularly important, and choices which are unnecessarily “wordy” should be avoided.

When given five choices, only one of which is grammatically correct, choose that one, even if it does use more words than are strictly necessary. If two of the choices are grammatically correct, but one of the correct choices is more succinct and uses fewer words than the other, choose the succinct version.

Don’t use “Because” to start a noun clause

The word “Because” should not be used to start a noun clause. A noun clause is any clause or part of a sentence that stands in place of a noun. The following sentence starts with an abstract noun (“the man’s guilt”) :

The man’s guilt does not mean that he should be executed.

In this variation on the sentence, the abstract noun has been replaced (correctly) by a clause:

The fact that the man is guilty does not mean that he should be executed.

Here the subject of the sentence is “the fact …” The following variation, on the other hand, is not correct:

Because the man is guilty does not mean that he should be executed.

Here a noun clause starting with “because” and that is not acceptable for GMAT. It is just about acceptable if you alter it slightly:

Because the man is guilty, it does not mean that he should be executed.

Technically, the subject is now “it”, but, even so, the sentence is still rather clumsy. It is always better to select an option such as the one starting “the fact that …” orthe following:

The man should not be punished just because he is guilty.

Comparison errors

He eats more than three men for breakfast.

This sentence contains a comparison error. Its meaning is ambiguous, because either the “he” of the sentence is being compared to three men or his appetite is being compared to that of three men. Does the sentence mean that he eats more than three men do, or that he eats four or five men for breakfast?

Comparison errors are similar to parallelism errors, in which two items which should be of the same form are lined up next to each other. However, in this case, the items are being specifically compared, and so the comparison must not only be grammatically correct (gerund compared with gerund, noun phrase compared with noun phrase etc.) but also sensible and unambiguous.