GMAT - Sentence Correction

Pronouns:  A pronoun stands in the place of a noun, so it must be clear what noun is being replaced.  Similarly, the pronoun must agree in number.

• “Bob and Fred enjoy fishing, even though he rarely catches anything.”  Who is he?  He could be Bob or Fred – it is impossible to tell from this sentence.

• “The average student enjoys music, and they can find it each Friday evening downtown.” Although “they” is incorrect, you probably immediately understood this sentence.  The noun  “student” is singular, however, so the pronoun must be singular as well.

Subject-Verb Agreement:  If the subject noun is singular, the verb must be as well.

• “The audience are pleased with the performance.”  Beware of nouns that sound plural, but are singular!  Although an audience can certainly be many people, the noun itself represents one audience.

Misplaced modifiers:  These sentences are easy to spot – look for the phrase with an -ing verb form followed by a noun.  Again, you may understand the sentence the first time, but a reread may make it sound somewhat off, and perhaps funny.

• “Running down the street, Jason’s knee gave out.”  This probably made sense to you, but look again.  Who was running down the street?  Jason?  Actually, the noun here is Jason’s knee (Jason is in the possessive form).  There are several ways to correct this sentence, ex., “Jason was running down the street when his knee gave out.”

Parallelism:   There several two types of parallelism issues, but simply, when you are looking at a list or parts of a sentence, make certain that the elements are in parallel.  For example:

• “Most people drink three cups of coffee, eat two pieces of bread, and walked one mile a day.”  This sentence contains a series of actions, but a closer examination shows that “walked” is in the past tense, but the other two verbs are in the present. 

• “He likes to run, to lift weights, and a healthy breakfast before leaving for the office each day.”  This is also a series question, but here the first two elements are verbs while the last element is a noun.  To fix this sentence, you might insert “to eat” before the “a healthy breakfast.”

• “To claim that the losing team is better is forgetting that the proof is in the final score!”  The two parts of the sentence must be constructed the same, so “to claim” should prompt “to forget” in the latter half. 

• “Dobermans bark more loudly than other dogs.”  You might say this aloud and find that it sounds fine.  It is understandable, but it is also incorrect!  What is it comparing?  Dobermans with other dogs?  No!  It is comparing how loudly they bark, so the sentence must end with “than other dogs bark” or “than other dogs do.”

Verb tense:  As you saw above, tense issues can show up in parallelism questions, and indeed, a sentence that depends on tense as an error must give you a clue. 

• “When she was in college, she played the guitar and has written several songs.”  The beginning of this sentence tells you that the verbs need to be in the past tense.  The general rule is that you should find the same tense in the same sentence.

• “He had walked only ten minutes when it started to rain.”

• This is the exception to the general rule!  “Had walked” is in the past perfect tense but “started” is in the past tense.  This is okay when once action in the past precedes another.

Idioms:  Listen to your ear, as there is no definite rule for these “common” means of expression.  Do a quick Google search on idioms, and you'll find countless databases that people have assembled.

• ”He must have typed the assignment, as no one could have read his handwriting.”  The “must have” has an idiomatic usage indicating that it “may be concluded,” so this is correct.