SAT Grammar Rules with Examples: Complete Guide for U.S. Students

Improving your grammar skills is one of the fastest ways to boost your SAT Writing and Language score. Unlike math, grammar is predictable—every question is based on a clear rule. Once you learn the rules and understand how the SAT tests them, you can consistently get high scores.

This guide breaks down all major SAT grammar rules, provides easy-to-understand examples, and includes strategies used by top SAT scorers across the U.S. Whether you’re aiming for a perfect 800 or simply want to improve your writing score, this article will give you everything you need.

Why SAT Grammar Matters

The SAT Writing & Language section evaluates:

• Grammar

• Punctuation

• Sentence structure

• Word choice

• Logical flow of ideas

The section includes 44 questions in 35 minutes, and more than half of them come from grammar rules, not reading comprehension.

Learning SAT grammar rules increases your score FAST because:

✔ The rules never change
✔ The test repeats similar patterns
✔ Wrong answers follow a predictable format
✔ A limited set of rules determines 80

Let’s break down the grammar rules you must know.

1. Subject–Verb Agreement

This is the most commonly tested grammar rule on the SAT.

Rule:

A verb must agree in number with its subject.

Common Traps on the SAT

• Subjects separated by long phrases

• Subjects appearing after the verb

• Collective nouns

• Singular nouns that look plural

Examples

Correct Example:

The list of U.S. national parks is impressive.

“List” is the subject, not “parks.”

Trick Example:

The players on the new basketball team was excited for the season.

❌ Wrong: was
✔ Correct: were

Subject = players, not team.

Inverted Structure:

Inside the museum are rare artifacts.

Verb comes before subject.

2. Pronoun Agreement

Rule:

Pronouns must match the nouns they refer to in number and clarity.

Common SAT Errors

• Ambiguous pronouns

• Singular “they” confusion

• Switching between he/she/they inconsistently

Examples

Ambiguous Pronoun:

When Jason spoke to Tom, he was frustrated.

Who is “he”?
SAT will consider this incorrect.

Correct Revision:

When Jason spoke to Tom, Jason was frustrated.

Pronoun Number Agreement

❌ Incorrect:
Every student must bring their ID.

✔ Correct:
Every student must bring his or her ID.

Even though “they” is accepted in modern writing, SAT prefers traditional grammar.

3. Modifier Placement (Dangling & Misplaced Modifiers)

A modifier must describe the correct noun.

Common SAT Error

Opening clause modifies the wrong subject.

Example:

❌ Wrong:
Running down the street, the backpack fell off Maria.

The sentence says the backpack was running.

✔ Correct:
Running down the street, Maria dropped her backpack.

4. Parallel Structure

Items in a list or comparison must follow the same grammatical pattern.

Examples

❌ Incorrect:
The program teaches students to write, reading, and how to analyze.

✔ Correct:
The program teaches students to write, to read, and to analyze.

OR

…writing, reading, and analyzing.

5. Verb Tense Consistency

SAT ensures verbs match:

• The time period

• The surrounding sentence

• The passage context

Examples

❌ Incorrect:
Lincoln led the nation through the Civil War and is leading the movement to abolish slavery.

✔ Correct:
Lincoln led the nation through the Civil War and led the movement to abolish slavery.

Both actions occurred in the past.

6. Comma Rules (One of the Most Tested Sections)

You must master comma usage. Here are the key rules.

Rule 1: Comma + FANBOYS = Correct only with two complete sentences

FANBOYS: For, And, Nor, But, Or, Yet, So

Example

✔ Correct:
The SAT is challenging, but it becomes easier with practice.

❌ Incorrect (Comma Splice):
The SAT is challenging, but becomes easier with practice.

Second half is not a complete sentence.

Rule 2: No comma between a subject and verb

❌ Incorrect:
Students preparing for the SAT, need consistent practice.

✔ Correct:
Students preparing for the SAT need consistent practice.

Rule 3: Commas for Non-Essential Clauses

Non-essential = optional information

✔ Correct:
The SAT, which is taken by students across the U.S., includes a Writing section.

If removing the clause still makes sense, use commas.

7. Semicolons and Colons

Semicolon Rule:

Use a semicolon to join two complete sentences.

✔ Correct:
The SAT is predictable; mastering grammar rules improves your score.

Colon Rule:

Use a colon after a complete sentence to introduce:

• A list

• An explanation

• Examples

✔ Example:
The SAT tests three major types of grammar skills: agreement, punctuation, and structure.

8. Sentence Fragments

A sentence must have:

• A subject

• A verb

• A complete thought

Example of Fragment:

❌ Incorrect:
Because the students prepared extensively for the SAT.

✔ Correct:
Because the students prepared extensively for the SAT, they felt confident.

9. Run-On Sentences

Two sentences joined incorrectly.

❌ Example:
The SAT is important it helps colleges evaluate students.

✔ Correct options:

The SAT is important because it helps colleges evaluate students.
OR
The SAT is important; it helps colleges evaluate students.
OR
The SAT is important. It helps colleges evaluate students.

10. Word Choice Errors (Diction)

SAT loves testing commonly confused words.

Examples

• affect (verb) vs. effect (noun)

• its (possessive) vs. it’s (it is)

• than vs. then

• accept vs. except

• compliment vs. complement

✔ Example:
Studying consistently will affect your SAT score.

❌ Incorrect:
…will effect your SAT score.

11. Idioms and Prepositions

Some phrases require specific prepositions.

Common SAT Idioms

• capable of

• interested in

• responsible for

• as a result of

• compared with

✔ Example:
Students are capable of improving their SAT grammar skills quickly.

12. Comparison Errors

Ensure you compare similar things.

❌ Incorrect:
The SAT score of Maria is higher than John.

✔ Correct:
Maria’s SAT score is higher than John’s score.

13. Redundancy and Wordiness

SAT prefers concise writing.

❌ Incorrect (redundant):
The reason is because students do not practice enough.

✔ Correct:
The reason is that students do not practice enough.

14. Active vs. Passive Voice

SAT generally prefers active voice unless context requires passive.

✔ Active:
The committee approved the new SAT rules.

Passive:
The new SAT rules were approved by the committee.

Both can be correct depending on context, but active tends to be clearer.

15. Transition Words

SAT tests logical connections such as:

• However

• Therefore

• Nevertheless

• Similarly

• Consequently

You must choose the word that matches the meaning—not just grammar.

Example

❌ Incorrect:
The student practiced daily. However, her score increased.

(“However” shows contrast, but there’s no contrast here.)

✔ Correct:
The student practiced daily. Consequently, her score increased.

16. Formal vs. Informal Tone

SAT passages maintain a formal academic tone.

❌ Too informal:
Kids get stressed when they think the test is super hard.

✔ SAT style:
Students often experience stress when they perceive the test as difficult.

17. Logical Order and Sentence Placement

SAT may ask where a sentence best fits.

You must check:

• Chronology

• Logical flow

• Topic consistency

• Transitional words

18. Apostrophes: Singular and Plural Possessives

Examples

✔ Singular possessive:
The student’s SAT book

✔ Plural possessive:
The students’ SAT scores

19. Essential vs. Non-Essential Clauses (That vs. Which)

• That = essential (no commas)

• Which = non-essential (commas)

✔ Example:
The book that she bought is helpful.
The book, which she bought yesterday, is helpful.

20. Combining Sentences Effectively

SAT asks for the clearest combination.

Avoid:

• Repetition

• Awkward phrasing

• Pronoun confusion

✔ Good Example:
Maria improved her score by practicing daily, which helped boost her confidence.

21. Consistency in Point of View

SAT avoids unnecessary shifts.

❌ Incorrect:
When students prepare early, one can reduce stress.

✔ Correct:
When students prepare early, they can reduce stress.

22. SAT Strategy: Plug-In Grammar

For tricky questions, plug in:

• Different nouns

• Different pronouns

• Different verb tenses

This reveals the correct answer.

23. SAT Grammar Question Types (Overview)

Here’s what you’ll face: