SAT Grammar Rules | All You Need to Know to Improve Your Grammatical Skills

Understanding Subject - Verb Agreement

As most SAT prep books we reviewed as well as SAT prep courses say, when preparing for the SAT® Writing Section, one of the most commonly tested topics is subject-verb agreement. As the name suggests, the "subject" and the "verb" must be in "agreement". In other words, if the subject is singular (the person, place or thing is just one), then there should be a singular verb used in the sentence. On the other hand, if the subject is plural (the person, place or thing is more than one), then there should be a plural verb used in the sentence.

Example #1:

Singular: Tom is a dentist that sees many patients.

Explanation: The person "Tom" is a singular subject. The verb "is" is used as a singular verb in this example.

Plural: Tom and Jerry are classmates from dental school.

Explanation: The person "Tom" and the person "Jerry" count as TWO people, which is more than ONE, so together it is a plural subject. The verb "are" is used as a plural verb in this example.

denist the dentist

Example #2:

girl is a good student

Singular: A good student needs to practice writing and grammar rules every day.

Explanation: The subject "A good student" is a singular subject. The verb "needs" is used as a singular verb in this example.

Plural: The bad students need to spend more time practicing writing grammatically correct sentences.

Explanation: The subject "The bad students", indicates more than ONE, so it is a plural subject. The verb "needs" is used as a plural verb in this example.

Using Collective Nouns

On the SAT® Writing and Language Test, students often mistake the correct subject-verb agreement rule when writing sentences using collective nouns. What are collective nouns?

Collective nouns are nouns that denote a group of individuals such as "assembly", "family", or "crew".

To get the SAT perfect score, one simple method is to remember the important grammar rule of subject-verb agreement in forming sentences, especially when seeing examples of collective nouns.

For SAT Writing (we compiled a full list of colleges that require SAT essay) and SAT Reading sections of the exam, be aware that collective nouns refer to multiple individuals in a group, but the word itself is considered a singular noun NOT a plural noun. Therefore, the subject will also be considered a singular subject, which means the correct subject and verb should be in agreement by using a matching singular verb.

Example #1:

Incorrect: The family go to the park for a picnic.

Correct: The family goes to the park for a picnic.

Explanation: The collective noun "family" is singular, so the subject in the sentence is a singular subject. The verb "go" is incorrect because it is a plural verb. The correct verb in this example is "goes" because it is a singular verb that matches the singular subject from the collective noun "family".

family on a picnic

Example #2:

Incorrect: The group eat lunch on the picnic tables at the park.

Correct: The group eats lunch on the picnic tables at the park.

Explanation: The collective noun "group" is singular, so the subject in the sentence is a singular subject. The verb "eats" is incorrect because it is a plural verb. The correct verb in this example is "eat" because it is a singular verb that matches the singular subject from the collective noun "group".

Finding Correlative Conjunctions

On the SAT Writing and Language Test, a common grammar error to detect on many questions is the use of correlative conjunctions.

What are correlative conjunctions?

Correlative conjunctions are pairs of conjunctions or conjunction phrases that connect clauses, phrases, or words together. Usually, the two elements that the correlative conjunctions connect are of similar length and grammatical structure.

Finding a simple error in matching correlative conjunctions is one way to increase your score on the SAT Writing and Language exam. Remember that correlative conjunctions come in pairs. It is good practice to circle the first word or phrase in the correlative conjunction pair, and then search for the other words or phrases in the corresponding pair.

Here are some common examples of correlative conjunctions.

Either ... or ...

Either Tom or Jerry is the favorite doctor in town.

No sooner ... than ...

No sooner had I finished writing the last sentence in than I realized I was actually writing the last week's assignment.

Both ... and ...

Both Sam and David work at the hospital.

not so much ... as ...

The teacher is not so much smart as he is witty.

Just as ... so ...

Just as Stephanie cooks dinner in the evenings so David cooks breakfast in the mornings.

Neither ... nor ...

Neither chewing gum nor skateboarding is allowed in the public park.

Identifying Prepositional Phrases

When writing a sentence, one of the most important SAT grammar rules is to correctly identify if a prepositional phrase is used as a singular subject or a plural subject.

Example #1:

Incorrect: The company of coworkers are very collaborative.

Correct: The company of coworkers is very collaborative.

Example #2:

Incorrect: The guidebook of 90 pages have many pictures.

Correct. The guidebook of 90 pages has many pictures.

Every sentence must correctly correspond with the correct subject and verb in the sentence.

good coworkers

Writing Correct Punctuation

It is critical to follow punctuation rules during the SAT Grammar Test. Finding a punctuation error in a sentence can easily add up to more points. This can also be applied to the ACT English exam. Deciding on the right answer to choose is a matter of finding an obvious error in the punctuation and correctly finding the right replacement. Just like in high school, the fundamentals of punctuation will be the most useful to quickly find an error and fix the sentence with the right answer. One little comma or period can make all the difference in the semantic meaning of the sentence.


Remember that hyphens are NOT the same as dashes.

Example #1

Use a hyphen when two or more words come before a noun to modify and act as a single idea (also called a compound adjective.

state-of-the-art building

on-campus recruiting

Example #2

Use a hyphen when using certain suffixes

The president-elect will start his term next month.

The restaurant-style French fries tasted amazing.

Example #3

Use hyphens for compound numbers and fractions

The train was going ninety-five miles per hour down the tracks.

One-half of the survey participants answered "yes."

When I was twenty-five years old, I graduated from law school.


A colon can connect two independent clauses, usually to signal a connection between them such as the following:

  • a list of items
  • direct quotation
  • salutation or greeting in a formal letter
  • linking two independence sentences, where the second sentence explains or elaborates on the first sentence

Example #1:

If you go to the fast-food restaurant, please buy the following menu items: hamburger, French fries, and medium diet coke.

Example #2:

One famous quote that inventor Thomas Edison said: "I have not failed. I've just found 10,000 ways that won't work."

Example #3:

Dear Mrs. Thompson:

Dear Sir or Madam:

Example #4:

The boy learned his lesson: never touch a hot stove.
colon vs semicolon


When separating two clauses that can function as independent stand-alone sentences, you MUST use a semicolon. The most common use of the semicolon (;) is to connect two closely-related independent clauses.

SAT Grammar Rule: Use a semicolon to improve the flow of ideas from one sentence to the other when the topic is generally the same or closely-related

Example #1: That restaurant is my favorite in the city; the food there is both delicious and affordable.

Example #2: Jonathan collects baseball cards; his collection includes over 800 valuable and unique cards.

Example #3: David plays many different musical instruments; he is so talented!

SAT Grammar Rule: 

Use a semicolon when writing a list and the items within the list include commas (e.g., city, state) to prevent confusion.

Incorrect: During our cross-country road trip, we passed through Des Moines, Iowa, Kansas City, Missouri, and Chicago, Illinois.

Correct: During our cross-country road trip, we passed through Des Moines, Iowa; Kansas City, Missouri; and Chicago, Illinois.

What is a comma splice?

When two independent clauses are incorrectly connected by using just a comma and not a semicolon, the error is known as a comma splice. Follow proper grammar rules

Incorrect: That restaurant is my favorite in the city, the food there is both delicious and affordable.

Incorrect:  Jonathan collects baseball cards, his collection includes over 800 valuable and unique cards. 

Incorrect: David plays many different musical instruments, he is so talented!


An apostrophe is often used when writing a contraction, a shortened form of a word (or group of words) that omits certain internal letters ad sounds.


should've = should have

He's = He is

They can't = They cannot

Another usage of apostrophes is when forming possessive nouns.


The man's mustache was very long.

Jones' house is down the street.


Also known as round brackets, parentheses are used normally for the writer to introduce remarks, side-notes, or other citations like abbreviations, translations, definitions, or examples.

Remember that parentheses can be thought of as adding additional information to a sentence, word, or phrase, but it is not necessary in the core meaning of the sentence. In other words, if the meaning of the sentence is still clear even without the parentheses or parenthetical remark, then the parentheses have been used correctly.

Example #1:

 Jennifer (who had lived in Spain before as a young child) knows her way around the city of Barcelona and speaks fluent Spanish.

Example #2:

Please take off your shoes before you enter the house (in order to avoid staining the carpet floors).

Quotation Marks 

Use quotation marks for direct quotes, titles of published work, or to imply alternate meanings.

Example #1:

David said, "The sky is blue."

Example #2

The 3rd chapter of the book is called "How to Get Into College".

Example #3

Let's just say the "deed" was done without any problems.


SAT Grammar Rule: Commas may surround non-essential phrases like appositives that directly follow the noun it modifies.

Example: George, a dashing young man, lives in the outer boroughs of Brooklyn.

SAT Grammar Rule: Use commas to address a person by name.

Example: Lebron, will you pass the ball already?

Choosing the Right Pronoun

What is a pronoun? A pronoun is a word that takes the place of a noun.

Some examples of a pronoun include: I, me, he, she, himself, herself, you, they, each, many, someone, everybody, everyone, who, whoever, and whose.

On the SAT exam, it is always a good idea to practice finding each pronoun and its original referenced noun. For example, you can draw a circle around a pronoun in a sentence and then draw an arrow to the actual exact noun (person, place, or thing) being referenced in the sentence. Also, make sure that the corresponding verb is in correct singular or plural form depending on the pronoun subject.

Example #1:

Incorrect: Although Jennifer was early for his job, he still forgot to bring his briefcase.

Correct: Although Jennifer was early for her job, she still forgot to bring her briefcase.

Example #2:

Incorrect: Please give the book to John or myself.

Correct: Please give the book to John or me.

Defining Modifiers Clearly

Misplaced modifiers is a common mistake for amateur writers and SAT Writing test-takers. Misplaced modifiers, also known as dangling modifiers, is a type of ambiguous grammatical construct where the modifier could potentially be misinterpreted as being associated with a word other than the word intended.

Incorrect: Sleeping on my bed, the alarm clock startled me.

Correct: Sleeping on my bed, I was startled by the alarm clock.

Correct Word Context in a Sentence

Previously, test-takers had to memorize hundreds of vocabulary words to be tested on the SAT exam. Luckily, for current test-takers, that part of the exam has been removed. The SAT Writing and Language Text, similar to the ACT English Test, both have questions on word choice that test on the word context given a certain sentence or sentences. These questions will test your knowledge of the correct usage of particular words in a specific context. \

What are homophones?

Homophones are words that sound similar with similar pronunciation but have a different meaning.

Example: heir and air

Definition: heir -- (noun) a person who inherits or has a right of inheritance in the property of another following the latter's death.

Definition: air -- (noun) a mixture of nitrogen, oxygen, and minute amounts of other gases that surrounds the earth and forms its atmosphere.

Example Question #1: Homophone

There are many countries that have the color red on there flags.

  • There, their (Correct Answer)
  • Their, their
  • Their, they’re
  • There, their
dont let them trick you

Example Question #2: Homophone

When driving, be sure not to suddenly slam on the breaks, because the car brakes easily.

  • breaks, breaks
  • brakes, brakes (Correct Answer)
  • brakes, breaks
  • bricks, breaks

It is best practice to choose among the answer choices using the process of elimination. When finding the correct answer choice to select, be sure to determine which part of the sentence is an independent clause or a dependent clause. Then make an educated guess if you are not completely sure of the right answer choice.

Follow Sentence Rules to Avoid Run-Ons and Fragments

Rules are rules as they say, so remember to obey the rules, especially when it comes to grammar rules when taking the SAT! It is always a good idea to check to see if the sentence you write is a run-on sentence or a fragment. People often are in a rush when writing or reading a sentence on the SAT, but it is a smart choice to slow down and really make sure a sentence is grammatically correct and proper.

Example #1:

Incorrect: I love cooking I would cook every day if I could.

Correct: I love cooking. I would cook every day if I could.

Example #2:

Incorrect: Some people are scared of the dark, they often prefer bringing a flashlight when going out at night.

Correct: Some people are scared of the dark. They often prefer bringing a flashlight when going out at night.

Verb Tense Consistency in a Sentence

Similar to the subject-verb agreement grammar rule, verb tense consistency in a sentence refers to keeping the same tense throughout a clause. It is grammatically incorrect to use two different tenses when using to describe just one time period. On the other hand, when there are two or more time periods, it is best to start a new clause or a new sentence. Catching a simple error early and often can lead to easy extra points on the exam.

Example #1:

Incorrect: David finished his homework, plays basketball, and ate a banana.

Correct: David finished his homework, played basketball, and ate a banana.

Example #2:

Incorrect: The DJ played funky music when the party started.

Correct: The DJ will play funky music when the party starts.


Remember to take multiple SAT practice tests in preparation for the official SAT exam weeks and months before the official SAT exam date. The new SAT exam will always be evolving, but the fundamental concepts and grammar rules will generally be the same. That's why it is always important to continue learning, even if it might seem repetitive. Remember repetition is key to practicing and reviewing test prep material.

Getting a high score on the College Board SAT exam, ACT exam, or other standardized test is all about preparation. Having a good routine in reviewing SAT prep material is critical for success on the SAT exam. Just like it is important to practice numbers and formulas for SAT Math prep, it is important to review words, sentences, and grammar for the SAT Essay section. Even though you might seem prepared, it is better to continually review your reading, writing, and grammar skills. This will also help down the line in the process of writing personal essays for college admissions.

Leonard Haggin

I created this site to help students like you learn from the experiences my team had learned during our extensive academic careers. I am now studying Law at Stanford, but I also make time to write articles here in order to help all you fellow students advance in your academic careers and beyond. I hope our efforts on Study Prep Lounge will arm you with the knowledge you need to overcome whatever trial or test you find in front of you.

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