Sentence Correction Question Types
There are a handful of question types that constitute the bulk of GMAT sentence correction questions. The ability to recognize these question types and understand what the GMAT test-writers are trying to test is imperative. Once you begin to recognize the format of these question types, the sentence correction section will become significantly easier as you will know exactly what is being tested and how to approach the question. The questions that follow are representative of the questions from each category. Pay careful attention to the answer explanation as it will explain the fundamentals of each category of question.
- Subject-Verb Agreement
- Verb Form
- Pronoun-Antecedent Agreement
- Logical Predication and Modifiers
Note: Some of the following questions have been simplified in order to illustrate the essence of the question type. Most GMAT sentence correction problems test multiple concepts and you should not expect to see one-concept problems.
Work additional sentence correction questions.
Identify the subject of the sentence (a spike) and the verb (strengthened). Notice that the subject is singular (a spike) while the verb is plural (have strengthened). Since the subject is in the non-underlined portion of the sentence, it cannot change. Consequently, the verb must become singular (has strengthened).
Since the context of the sentence shows that the action is continuous, you must use the present perfect tense (has strengthened) instead of the simple present tense (strengthen). In other words, since the spike in consumer sentiment occurred in the past and is still occurring today, you cannot use the simple past tense nor can you use the simple present tense.
- subject and verb do not agree; and the economy rebound is awkward and not parallel with will increase
- strengthened should be in the present perfect tense to reflect the ongoing nature of the action; a rising of domestic spending and the economy rebounding should be parallel; a rising of domestic spending is wordy and awkward
- strengthened should be in the present perfect tense to reflect the ongoing nature of the action; the phrase spending will increase as the economy rebounds distorts the original intent of the sentence as it places the economic recovery ahead of the increase in sales instead of placing the two events in parallel as the original sentence does
- spending on domestic items is wordy and could be replaced by the more concise phrase domestic spending; eventually is redundant and unnecessary as will increase already implies a future action
- the subject and verb agree; the verb is in the correct tense; the two parts of the phrase domestic spending will increase and the economy will rebound are parallel
The Embassy urged the expats to do three things: (1) remain vigilant (2) avoid the Blackburn district (3) refrain from late-night travel. A list of actions or commands that occur together in time should be parallel.
In this sentence, the final action is not currently parallel with the first and second actions (i.e., refraining is not parallel with remain and avoid). In order for the sentence to be parallel, all verbs need to be in their infinitive form since remain and avoid are in the infinitive form and cannot be changed.
When parallel, the sentence should read: to remain vigilant, avoid the Blackburn district, and refrain...
- refraining, which is not in infinitive form, is not parallel with to remain and [to] avoid; note that the [to] is understood in front of avoid as avoid is in the infinitive form
- traveling, which is not in infinitive form, is not parallel with to remain and [to] avoid
- as an imperative, is wordy and redundant; as an imperative, prevents the three Embassy instructions from appearing in a parallel list
- refraining, which is not in infinitive form, is not parallel with to remain and [to] avoid; leaving a secure area is wordy and could be replaced by one word--traveling
- the three commands are all listed in parallel, each using the infinitive form; redundant phrases such as leaving a secure area are avoided
The GMAT is extremely particular when it comes to idioms. The test-writers expect you to know a list of idioms and use them--even when alternative phrases are grammatically correct and commonly used. It is imperative that you review the GMAT idiom list.
This question tests your knowledge of the idiom to credit x with. Consequently, sentences that read credit Athanasius of Alexandria for or credit Athanasius of Alexandria as are not correct.
having single-handedly defeated is wordy and can be replaced with single-handedly defeating.
- to credit x requires with, not for; to credit for is idiomatically incorrect; having is unnecessary as a simpler verb tense can be used
- the correct idiom is used (i.e., to credit x with); the unnecessary word having has been eliminated
- to credit x requires with, not as;
- to credit x requires with, not as; having is unnecessary as a simpler verb tense can be used
- having is unnecessary as a simpler verb tense can be used
In questions about verb form, it is essential that you construct a mental timeline of the events in the question so that you can use the appropriate verb tense.
In this question, the prime suspect commits the crime then the police examine the fingerprint, concluding that the prime suspect committed the crime. The key insight in this question is seeing that the crime occurred before the police investigated.
For sentences where events occur at different times in the past, you need to use the past perfect tense for the earlier action and the simple past tense for the more recent action. In this question, had committed is correct since the crime occurred before the police conducted the investigation and reached their conclusion.
- committed should be in the past perfect tense not the simple past
- would commit is in the future tense yet every action occurred in the past--the police cannot investigate a crime that has not yet occurred
- the sentence correctly uses the past perfect tense to indicate that one action occurred before the other in the past
- did commit is not the perfect past, which is needed since two events in the past occurred at different times
- was committing is not the past perfect tense; this sentence illogically indicates that the police investigated crime scene while the theft occurred
The pronoun and antecedent (Jackson Computer Specialists) must agree (i.e., a singular pronoun must refer back to a singular noun). Since the pronoun is singular, the antecedent must also be singular. If you are unsure about whether the antecedent is singular, note the use of a large regional consulting firm, which indicates that the noun is singular. Note as well that there is a difference between referring to the firm (singular) and the employees of the firm (plural).
Since the antecedent in this question is singular (a large regional consulting firm), the pronoun should be singular (it).
- the plural pronoun they does not agree with the singular noun
- the intention of expanding is awkward and unidiomatic
- the plural pronoun they does not agree with the singular noun
- the plural pronoun their does not agree with the singular noun
- the singular pronoun it agrees with the singular noun
Logical Predication and Modifiers
The first part of the sentence acts as a modifier; it modifies the noun (political historians) that follows the comma. However, the modifier incorrectly modifies some political historians. Political historians are not based on first-hand accounts. Rather, political historians use first-hand accounts.
- Based on... incorrectly modifies political historians
- Using first-hand... correctly modifies political historians
- Basing their conclusions in is awkward and unidiomatic; conclusions is redundant as the word is mentioned later; basing incorrectly modifies political historians
- With incorrectly modifies political historians; first-hand accounts in is awkward and unidiomatic
- With is unnecessary as use (it should be using) conveys the same idea; the entire phrase is awkward
The intention of this sentence is to indicate the author's comparison of Chinese regulators with American regulators. But, the original sentence compares the country China with American regulators. Note that the phrase American regulators is placed outside the underlined portion of the sentence and as a result, it cannot change.
You cannot logically compare unlike parts (i.e., comparing a country, China, to another country's regulators, American regulators). Since American regulators cannot change, you must use Chinese regulators in order to logically compare similar elements (i.e., compare regulators with regulators).
- wrongly compares China (a country) to American regulators (people)
- correctly compares Chinese regulators (people) to American regulators (people)
- wrongly compares China's system of regulation (a system) to American regulators (people)
- wrongly compares Chinese regulations (laws) to American regulators (people)
- wrongly compares China's regulations (laws) to American regulators (people)