Knewton GMAT Prep Tip: Common SC Errors

by , May 14, 2010

This guest post is written by Jen Rugani. She is a Knewton GMAT Instructor and Sentence Correction expert.

Pop quiz! Choose the correct construction in the five exercises below. These arent particularly challenging sentences, but they all test your understanding of some tricky errors that pop up all the time on the GMAT. If you understand these grammar rules at a conceptual level, then youll be able to master them on even the toughest of SC questions.

1)

a) She tried to remember how to throw a boomerang, eventually it came back to her.

b) She tried to remember how to throw a boomerang, and eventually it came back to her.

2)

a) I work more quickly after I drink six Red Bulls.

b) I work quicker after I drink six Red Bulls.

3)

a) I had already purchased tickets to a Justin Bieber concert when I realized that I had the musical taste of a twelve-year-old.

b) I already purchased tickets to a Justin Bieber concert when I had realized that I had the musical taste of a twelve-year-old.

4)

a) The principal said that he was closing the school, which made most of the parents angry.

b) The principal said that he was closing the school, an announcement that made most of the parents angry.

5)

a) The taste of the chocolate cake, like the tiramisu, is sinfully delicious.

b) The taste of the chocolate cake, like that of the tiramisu, is sinfully delicious.

Answers and Explanations

1) Answer: b

Common GMAT Error: Clause Connection

The key here is to look for clauses that can stand on their own as complete sentences by identifying main subject-verb pairs. Here, we have two main subject-verb pairs (she tried it came), so we have to make sure that these independent clauses are connected correctly. There are two correct ways to connect them: a semi-colon or a comma + coordinating conjunction. A comma on its own can NEVER connect two independent clauses.

Coordinating conjunction is an annoyingly academic term, so it can be easier to remember these words as the FANBOYS: For, And, Nor, But, Or, Yet, So. These wordsand only these wordscan follow a comma to connect independent clauses. Dont be distracted by an imposter word like however; even though it sounds like a synonym for but, it cant connect independent clauses.

2) Answer: a

Common GMAT Error: Adjectives versus Adverbs

The GMAT loves to test long, complicated modifier phrases, but some of the trickiest modifier errors come down to just one word: an adjective or an adverb. These can be particularly frustrating for native English speakers, because its easy for your ear to betray youwe often misspeak these in everyday life. Take a step back and look at the logic of this sentence: What word is actually being modified? What thing happens more quickly/quicker? Its the work that is logically being described.

Because youre a diligent GMAT student and have been studying your grammar rules, you know that adjectives modify nouns and adverbs modify verbs, adjectives, and other adverbs. Is work a noun? Nope! Its a verb, so you know it has to be modified by an adverb. Identify the adverb by its ly ending; most English adverbs end this way.

3) Answer: a

Common GMAT Error: Complex Verb Tenses

Logic checks are extremely helpful in sorting out verb tense errors, particularly when dealing with complex tenses like the past perfect. Ask yourself: What are the events that take place in the sentence? In what order did they logically occur? In this sentence, we have two events: the purchase of the tickets and the realization. Both of these events logically occurred in the past, but the purchase of the tickets happened first. Whenever the past perfect tense (had + past participle) appears in a sentence, make sure that the tense is used to describe the event that happened before another event in the past.

Notice the use of the word already as an extra indicator of the logical order of events. Could this bethe GMAT giving you a clue? Yes! If youre having trouble establishing the chronology of the sentence, look for time clue words like already, before, since, and until.

4) Answer: b

Common GMAT Error: Dangling Modifiers

Grammar Rule Alert: Relative pronouns (who, whom, whose, that, which) must be immediately next to the noun they logically describe. In choice A here, the noun closest to which is school. But is it the school that made most of the parents angry? No, its the principals announcement. In fact, there is no noun in choice A that the relative pronoun can logically modify, resulting in a dangling modifier.

Answer choice B has fixed this error by introducing the missing noun, announcement. Now, the relative pronoun that correctly refers to announcement, and the logic of the sentence stays intact. If you see a dangling modifier on the GMAT, look for an answer choice that introduces the missing noun the test will often use this method to fix the error.

5) Answer: b

Common GMAT Error: Logical Comparisons

This is another error that can be tricky to spot because its often misspoken in everyday use. Whenever items are compared on the GMAT, they have to be in the same category; that is, they have to be logically comparable. In this example, we can compare dessert to dessert or taste to taste. Answer choice A compares dessert to taste, resulting in a comparison error.

Answer choice B uses the singular pronoun that to fix the comparison. We could say, The taste of the chocolate cake, like the taste of the tiramisu but the pronoun is just as correct. Keep your eyes open for these noun-pronoun comparison structures; the GMAT loves to test them.