Overview
This guide covers fundamental SAT grammar rules, including punctuation, possessives, subject-verb agreement, and essential versus nonessential clauses, with tips for improving SAT Reading & Writing scores.
Commas
- Use commas to separate independent clauses joined by FANBOYS (For, And, Nor, But, Or, Yet, So).
- Place a comma after introductory phrases or modifying clauses.
- Use commas to separate items in a list of three or more.
- Set off nonessential information with commas.
- Separate dependent and independent clauses when the dependent clause comes first.
- If a dependent clause starts with an -ing verb after an independent clause, use a comma.
Semicolons
- Join two independent clauses without a FANBOYS conjunction using a semicolon.
- Use semicolons to separate items in a list that already has internal commas.
- Semicolons can often be replaced by periods; if both are options, they may both be incorrect unless in complex lists.
Colons
- Introduce or emphasize a short phrase, explanation, question, example, or list.
- Always place a colon after an independent clause.
Apostrophes (Contractions & Possessives)
- Use an apostrophe + s to show singular possession (one person owns something).
- Use s + apostrophe to show plural possession (multiple people own something).
- Omit apostrophes for plural nouns if not showing possession.
- Use apostrophes to indicate contractions (e.g., he's = he is).
Subject-Verb Agreement
- Subjects and verbs must agree in number: singular subject with singular verb, plural subject with plural verb.
- Ignore prepositional phrases between the subject and verb when deciding agreement.
- Remove words between the subject and verb to clarify agreement.
Nonessential vs. Essential Clauses
- Nonessential clauses add extra information, are removable, and are set off by matching commas or dashes.
- Essential clauses provide necessary information, are not set off by commas.
Key Terms & Definitions
- FANBOYS — For, And, Nor, But, Or, Yet, So; coordinating conjunctions.
- Independent Clause — A sentence that can stand alone, containing a subject and verb.
- Dependent Clause — A fragment that cannot stand alone as a sentence.
- Nonessential Clause — Extra information that can be removed without changing the sentence’s meaning.
- Essential Clause — Necessary information to identify the subject, not set off by commas.
- Subject-Verb Agreement — The subject and verb must both be singular or both be plural.
Action Items / Next Steps
- Practice applying these rules to real SAT grammar questions.
- Remove prepositional phrases mentally when checking subject-verb agreement.
- Identify and punctuate essential vs. nonessential clauses in practice sentences.