The Grammar Rules You Must Know for SAT Writing
Here are the 12 SAT grammar rules that you need to learn and understand before test day.
#1: Select the Correct Word Based on the Context of the Given Sentence
Word choice questions are common on the SAT. A word will be underlined, and based on the context, you have to
select the best word to complete the sentence. These questions can be difficult because they require knowledge of
vocabulary. There are two common types of word choice questions.
Type #1: Homophones
Homophones are words that sound the same but have different meanings. Here are some examples of homophones
that have appeared on the practice SATs: fare/fair, cite/sight/site, then/than, there/their/they're, and its/it’s.
You should know what each of these words means and how it's used.
SAT Example
The sentence is comparing the cafe to a fair. Based on the context, the word “fair,” which means an exhibition,
usually with food and entertainment, is correct. There are multiple meanings of the word “fare,” but it often refers to
the money you pay for transportation, as in “bus fare.” Clearly, the word “fare” doesn’t make sense in this context, so
you can immediately eliminate answer choice C.
Next, we need to determine if we should use “then” or “than.” You use the word “than” to make comparisons and
“then” to refer to time. Because the sentence is comparing the cafe to a fair, the correct answer is B.
Type #2: Related Words
The second type of word choice error involves synonyms or related words. A word will be underlined and the answer
choices will be related words. However, only one word will be correct given the context of the sentence.
SAT Example
For these types of questions, I like to quickly go through each choice to see which one makes the most sense given
the context. Based on the context of this sentence, we’re looking for a word that indicates that the officials gave
permission for the cat paintings to be made.
The word “forced” sounds too strong in this context, and generally, you don’t “license” a painting to be made. The
word “decreed,” which means to order or command, also seems too harsh given the context. The word
“commissioned” can mean hiring an artist to create a work. It’s the only word that’s typically used with artwork, and
it’s the most appropriate word for this sentence. The correct answer is B.
It’s difficult to prepare for these questions because you don’t know the specific words that will appear on the SAT.
However, I recommend using the word choice questions on the practice SATs to help you study. Also, try to identify
the subtle differences in the meanings of the words in the answer choices to help select the best word to complete
the sentence.
#2: Use the Fewest Words Possible
Typically, the shortest grammatically correct answer choice that expresses the same information as the original
sentence will be the right answer. Shorter sentences are more concise and easier to understand. On the SAT, words or
phrases may be unnecessarily added to a sentence. Here’s an example sentence with a redundancy error:
Every year, Jane runs the Los Angeles Marathon annually.
In this sentence, the word “annually” means that she runs the marathon every year. Because the sentence starts with
“every year,” the word “annually” is unnecessary. It doesn’t add any new information to the sentence, and it should
be eliminated.
Here’s another example of a wordy sentence:
George is a person who is angry in nature.
This is a corrected version of the sentence:
George is an angry person.
The corrected sentence conveys the same information as the original but in a much more concise manner.
SAT Example
Answer choices A, B, and C are redundant. The phrase “and other countries” already implies that there are other
items on the list. The correct answer is D.
#3: Use the Correct Idiomatic Expression
Idiom questions can be challenging because they don't conform to specific rules. You have to rely on your
knowledge of specific phrases and standard English conventions to answer these questions correctly. In most idiom
questions on the SAT, you'll be asked to determine which preposition to use in a given sentence. Check out this
example sentence with a prepositional idiom error:
Incorrect: After getting suspended, Herbert decided to focus at improving his behavior.
Correct: After getting suspended, Herbert decided to focus on improving his behavior.
There is no rule to learn to help identify this error, but the correct expression is "focus on."
SAT Example
The correct expression is “as a means of,” and the answer is B. Study the idiom questions from the practice SATs, and
review my article on SAT idioms to prepare yourself.
#4: Keep Verb Tenses Consistent
The general rule regarding verb consistency is that verbs should remain consistent in tense or form throughout a
sentence. Here’s an example of a consistency error:
Last week, Frank rented a car and drives to Las Vegas.
The verb “drives” should be in the past tense. Not only should “drives” be consistent with the past tense “rented,” but
also the phrase “Last week” indicates that this was something that happened in the past. This is the corrected version
of the sentence:
Last week, Frank rented a car and drove to Las Vegas.
Also, on the SAT, the verb tenses of surrounding sentences can provide context clues for the proper tense to use in a
given sentence to maintain consistency. Here’s another example of a consistency error:
Trenton lives in a rural area. He enjoyed the peace and quiet.
The shift from the present tense “lives” to the past tense “enjoyed” doesn’t make sense in context. Here is a corrected
version of the sentence:
Trenton lives in a rural area. He enjoys the peace and quiet.
SAT Example
In this sentence, the verbs “is” and “serves” indicate that the underlined verb should be in the present tense. Answer
choices B and D are not present tense verbs. Answer choice A is wrong because the “it” is redundant. The correct
answer is C.
#5: Surround Non-Restrictive Clauses and Appositives With Commas
The SAT tests a number of comma rules, and these are two that you need to know.
Relative Clauses: Restrictive vs. Non-Restrictive
Relative clauses are dependent clauses that describe a noun and start with a relative pronoun or adverb like “who,”
“that,” “which,” or “where.” The basic rule is that restrictive clauses shouldn’t be surrounded by commas and nonrestrictive clauses should be.
What’s a Restrictive Clause?
Restrictive clauses are necessary to the meaning of the sentence. You can’t take a restrictive clause out of a sentence
without effectively changing the meaning of the sentence. Here’s an example:
Students who read regularly are prepared for the SAT.
If you remove the clause “who read regularly,” the meaning of the sentence would be substantially changed. You’d
be left with “Students are prepared for the SAT.” Because you can’t remove the clause without changing the
meaning of the sentence, this clause shouldn’t be surrounded by commas.
What’s a Non-Restrictive Clause?
A non-restrictive clause isn't essential to the meaning of the sentence. If you got rid of the clause, you'd have less
information, but the overall meaning of the sentence would remain the same. Here's an example sentence with the
non-restrictive clause underlined.
Joe’s parents, who constantly call him, are very overprotective.
The clause “who constantly call him” adds more information about Joe’s parents, but if it were removed, the meaning
of the sentence would be the same. There would be less information about Joe’s parents, but they would still be
described as overprotective. This is what the sentence looks like after removing the non-restrictive clause:
Joe’s parents are very overprotective.
What Is an Appositive?
An appositive is a descriptive phrase that doesn't include a verb. Similar to a non-restrictive clause, an appositive
can be removed without changing the meaning of the sentence. Here's an example with the appositive underlined:
Val, a Wisconsin native, loves fried cheese curds.
If we get rid of the appositive, the sentence still has the same meaning:
Val loves fried cheese curds.
SAT Example
In this sentence, “the centerpiece” is an appositive that adds more information about the mural. Because appositives
must be surrounded by commas, there should be a comma after “centerpiece.” Immediately, we know that A and C
are wrong. In answer choice D, the dash can be used like a comma, but you can’t separate a clause with a comma and
a dash. There would have to be a dash after “mural” for answer choice D to be right. The correct answer is B.
#6: Commas Can't Separate Two Complete Thoughts
A comma splice is when two independent clauses, or complete thoughts, are separated by a comma, and comma
splices create a grammatical error known as a run-on sentence. A run-on sentence occurs when two or more
independent clauses aren't separated by the correct punctuation. Here’s an example of a comma splice:
Ken likes Selena Gomez, she is his favorite singer.
The clauses before and after the comma are complete thoughts that could stand alone as sentences. There are a few
ways to correct a comma splice. You can put a conjunction after the comma:
Ken likes Selena Gomez, and she is his favorite singer.
Also, you can put a relative pronoun after the comma:
Ken likes Selena Gomez, who is his favorite singer.
Finally, you can use a semicolon to correctly separate two complete thoughts:
Ken likes Selena Gomez; she is his favorite singer.
SAT Example
This is an example of a comma splice. The sentence up until “legs” is a complete thought that could stand alone as a
sentence, and the rest of the sentence starting with “they” is also a complete thought. Both A and B are comma
splices. Answer choice D is wrong because a conjunction is needed to connect “are characterized” and “are
covered.” The correct answer is C.
#7: Semicolons Separate Two Complete Thoughts
Semicolons function like periods; they separate two independent clauses. You should be able to replace semicolons
with periods. On the SAT, you may find a randomly placed semicolon, or you may need to replace a comma with a
semicolon to fix a comma splice.Here are example sentences with semicolons used correctly and incorrectly:
Incorrect: Because Teresa wanted to please her family; she became a doctor.
Correct: Teresa wanted to please her family; she became a doctor.
The second sentence is correct because the clauses on both sides of the semicolon are independent and could stand
alone as sentences.
SAT Example
The clause before the semicolon is not a complete thought; therefore, the semicolon is being used incorrectly.
Answer choice C unnecessarily adds “and,” and answer choice B is wrong because it places a colon after a
dependent clause. The correct answer is D.
#8: A Colon Must Come After an Independent Clause
Colons are usually used to introduce lists or explanations. The key rule for colons is that they must come after a
complete sentence. If you end the sentence where the colon is placed, the sentence should make sense and be a
complete thought.
Incorrect: Meena enjoys multiple genres of music like: alternative, rap, heavy metal, and country.
Correct: Meena enjoys multiple genres of music: alternative, rap, heavy metal, and country.
The first sentence is incorrect because the part of the sentence that comes before the colon isn’t a complete thought.
SAT Example
Because the clause before the colon is a complete thought and it's setting up a list, the colon is being used correctly.
The types of people listed after the colon are the narrator's colleagues. Because "colleagues" isn't part of the list, you
can't substitute the colon for a comma. Also, you can't use a semicolon in place of the colon because there isn't a
complete thought after the punctuation. The correct answer is A.
#9: Use Apostrophes Correctly to Form Possessives
The SAT tests you on how to use apostrophes to correctly form possessives. Luckily, the rules for forming possessives
are pretty straightforward. If the word is singular or plural but doesn’t end in “s,” then you add an “s” after the
apostrophe to form a possessive. Here are a couple of examples:
I shall be paying a visit to the men’s restroom.
My computer’s monitor is rather dirty.
To create a possessive for a plural word that does end in “s,” just add an apostrophe after the “s.” Check it out:
Juan thinks his parents’ rules are too strict.
Also, only use apostrophes for possessives or contractions. Contractions are formed when you combine two words.
Examples include it’s (it is), don’t (do not), and isn’t (is not). Don’t use apostrophes to create plural nouns.
SAT Example
Because the body is is being discussed in general terms, we should use the singular possessive in this sentence; the
sentence is referring to the biological clocks of the body. We can immediately get rid of A because “bodies” is a
plural noun; it’s not in the possessive form.
Also, answer choice B is wrong because bodies’ is the plural possessive form. Additionally, there shouldn’t be an
apostrophe after the “s” in “clocks.” Don’t use apostrophes to form plural nouns; only use apostrophes for possessives
and contractions. Similarly, answer choice D is wrong because of the apostrophe before the “s” in clocks; the correct
answer is C.
#10: Subjects and Verbs Must Agree
Subjects and verbs must agree, meaning that you must use the singular form of a verb with a singular subject and the
plural form of a verb with a plural subject. Here’s an example:
Incorrect: High school students loves learning grammar rules.
Correct: High school students love learning grammar rules.
If the verb is in the present tense and the subject is in the third person (he/she/it/they), the verb usually ends in “s”
in the singular form and doesn’t in the plural form. In the example sentence, the subject is “students,” which is plural;
therefore the verb should be in the plural form.
On the SAT, subject verb agreement questions can be more difficult because there may be a phrase separating the
subject from the verb. Check out this example:
Incorrect: The members of the committee meets every Tuesday.
Correct: The members of the committee meet every Tuesday.
The subject of the sentence is “members,” which is plural. Therefore, the verb should be in the plural form. The
prepositional phrase “of the committee” separates the subject from the verb. If a verb is underlined on the SAT, make
sure that you identify the subject that corresponds with that verb to ensure that the subject and verb agree. Also,
keep in mind that a subject can never be part of a prepositional phrase.
SAT Example
To determine if there’s a subject verb agreement error, we have to identify the subject that corresponds with the
verb “portrays.” What portrays animals? The works of art do. The phrase in between the commas separates the
subject from the verb. The subject is plural because “works” is plural and “of art” is a prepositional phrase. The plural
form of “portrays” is “portray,” and the correct answer is C. Answer choices B and D are not plural verbs;
“portraying” is a gerund that would create a fragment, and “has portrayed” is the singular form of the present
perfect tense.
#11: Modifiers Must Be Next to What They're Modifying
The general rule regarding modifiers is that they must be next to what they’re modifying. The most common type of
modifier error on the SAT is a dangling modifier. When a sentence begins with a modifying phrase, the introductory
phrase must be immediately followed by a comma and then the noun the phrase is describing. Here’s an example of
a dangling modifier:
A determined writer, Jessica’s goal is to get her first novel published this year.
The way the sentence is written makes it seem like Jessica’s goal is a determined writer. There are a couple of ways
to fix the sentence. You can place the noun that is being modified right after the comma:
A determined writer, Jessica has a goal of getting her first novel published this year.
Or you can place the subject in the introductory phrase:
Because Jessica is a determined writer, her goal is to get her first novel published this year.
SAT Example
This sentence makes it seem like the visitor was dotted with pin-sized knobs. Logically, the sentence should indicate
that the drawers were dotted with pin-sized knobs. Similarly, answer choices B and C are misplaced modifiers that
infer that the there was a visitor dotted with knobs. The correct answer is D.
#12: Pronouns Must Agree With Their Antecedents in Number
This rule means that a plural pronoun must refer to a plural noun and a singular pronoun must refer to a singular
noun. Here's an example of a pronoun number agreement error:
Kristin sold their car.
The pronoun “their” is referring to the car of Kristin. Because Kristin is one person and “their” is a plural pronoun, this
sentence has a pronoun agreement error. This is the corrected version:
Kristin sold her car.
SAT Example
It’s easy to make a careless mistake on this question because you may see the singular pronoun “it” and assumed the
underlined pronoun should be singular as well. However, the pronouns have different antecedents. The word “it”
refers to 1-MCP, which is singular, and “their” refers to apples, which is plural. The possessive pronoun agrees with
the antecedent, and there’s no error.
Answer choice A is correct. Answer choice C is a singular possessive pronoun, D is the contraction of “it is,” and B is a
homophone of the correct answer, but it’s the wrong word.