Sentence Correction Grammar Essentials

Subject-Verb Agreement

Subject–The noun performing the action in a sentence.

Verb–The action being performed.

The subject of the sentence and the action verb must agree in number.

In general, subjects that are singular and in the Third Person will take one set of verbs and all other subjects will take another set of verbs. The Third Person means that the noun refers to a person or thing that is not the speaker (“I”) or the person being spoken to (“you”).


He walks.

They walk.

You walk.

He reads.

They read.

You read.

Sometimes on the GMAT, the subject and verb will be separated by words or clauses. It is important that you properly identify the subject and verb before checking for subject-verb agreement.


Personal Pronouns

Personal pronouns take on different forms depending on their function in a sentence. Identify how a pronoun is being used (subject, direct object, indirect object, etc) and then you will be able to figure out the proper form.

Subject Direct Object
First Person (s) I Me
First Person (pl) We Us
Second Person (s) You You
Second Person (pl) You/you guys/y’all You/you guys/y’all
Third Person (s) He/she/it Him/her/it
Third Person (pl) They Them


Personal pronouns have possessive forms that act as adjectives and forms that act as nouns. In general, the adjective form should only be used in conjunction with the noun it modifies. The noun form is used to replace noun that


Here are your papers. (Adjective form)

Here are yours. (Noun form)

Adjective Noun
First Person (s) My Mine
First Person (pl) Our Ours
Second Person (s) Your Yours
Second Person (pl) Your Yours
Third Person (s) His/her/its His/hers/its
Third Person (pl) Their Theirs

Verbs, Participles, and Gerunds


A descriptive word (adjective or adverb) formed from a verb.

The two most common categories of participles in English are present participles and past participles. Present participles are formed by adding -ing to the end of the verb. Past participles are often formed by adding -ed, but there are exceptions to this rule. For most verbs, the past participle is the same as the past tense form.

Examples of participles:

Present Form of Verb Present Participle Past Participle
Lift Lifting Lifted
Eat Eating Eaten
Fight Fighting Fought
Be Being Been
Study Studying Studied
Sit Sitting Sat

Examples of participles used in sentences:

The running man read yelled.

The politician, elected in a landslide, claimed a mandate for his agenda.

The barking dog chased after the mailman.

The torn book had clearly sat on the shelf for many years.

Note that participles cannot function as the main verb of the sentence.


Gerunds look like present participles but act as nouns.

Examples of Gerunds:

Studying is necessary to get a good score on the GMAT.

She knows how to sing, but her dancing could use some work.

Writing is difficult if you do not practice.

Gerunds can also be a part of a larger phrase that includes other elements, such as a direct object or prepositional phrase.

Examples of Gerund Phrases:

Studying both mathematics and grammar is necessary to get a good score on the GMAT.

People said that running a mile in under four minutes was impossible.

In the United States, selling alcohol to children under 21 years old is illegal.

Parallelism and Verb Tense Consistency


In lists or comparisons, each element must maintain the same structure and all verbs must be in the same form. This is one of the most common errors in the Sentence Correction section.

Example: Next week, all students will rest, study, and take their exams. (Correct)

Next week all students will rest, studying, and will take their exams. (Incorrect)

Verb Tense Consistency

In most cases, the tense of verbs should stay consistent within a sentence.

Example: The student studies and reads every night. (Correct)

The student studied and reads every night. (Incorrect)

Sometimes the tense of the verb is not as obvious. There are several different tenses in the present, past, and future. Additionally, each tense can be either not-continuous or continuous. Verbs do not necessarily all need to be continuous or not-continuous, unless they are used in a parallel structure

Overview of English Verb Tenses:

Not-Continuous/Simple Continuous
Present She drives She is driving
Past She drove She was driving
Present Perfect She has driven She has been driving
Past Perfect She had driven She had been driving
Future Perfect She will have driven She will have been driving
Future She will drive She will be driving

Adverbs and Adjectives

Adverbs describe verbs and adjectives. Adverbs include “well” and most words that end in “-ly”.

Adjectives describe nouns.

Adjectives cannot describe verbs or adjectives. Adverbs cannot describe nouns.


Idioms are expressions that have a meaning separate from their individual words. These are especially difficult for people who do not speak English as a first language. The most effective way to learn idioms is to read frequently.

Common Idioms on the GMAT:

  • Not only X but also Y
  • Prefer X to Y
  • In contrast to/with X,  Y
  • Amount of…
  • X consider Y Z
  • Just as X, so too Y
  • Worry about X
  • Concerned about X
  • Between X and Y