Top 10 SAT Grammar Rules: Punctuation, Verbs & Boundaries
Master the 10 rules that cover 100% of SAT grammar questions.
The top 5 most tested SAT grammar rules are: 1. Independent Clause Boundaries: Two complete sentences require a period, semicolon, or comma + FANBOYS (never a lone comma). 2. Colons & Single Dashes: Must follow a complete independent clause. 3. Subject-Verb Agreement: Match the subject across interrupting prepositional phrases. 4. Dangling Modifiers: An introductory modifier must touch the noun performing the action. 5. Apostrophe Ownership: Its (possessive) vs It's (it is).
Standard English Conventions questions are 100% objective and rule-based. Memorizing these 10 rules eliminates guesswork.
Step-by-Step Breakdown & Rules
1. Semicolons Connect Two Complete Sentences
[Independent Clause] ; [Independent Clause]. Semicolons function identically to periods on the SAT.
2. Avoid Comma Splices
Never join two complete independent clauses with only a comma. Use a semicolon, period, or comma + FANBOYS (for, and, nor, but, or, yet, so).
3. Colons Require a Full Sentence Before the Colon
[Complete Sentence] : [List, Explanation, Fragment, or Sentence].
4. Non-Essential Clauses Need Matching Punctuation Pairs
Surround non-essential information with two commas (A, B, C) or two dashes (A — B — C), never mix a comma with a dash.
5. Subject-Verb Agreement Ignores Prepositional Phrases
Cross out prepositional phrases like "of the students" to match the main subject: "The list of students [is/are]" -> "list is".
6. Dangling Modifiers Must Touch the Subject
"Walking to school, the backpack felt heavy" is incorrect because the backpack was not walking. Fix: "Walking to school, Sarah felt her backpack..."
7. Parallel Structure in Lists and Comparisons
Items in a list or comparison must maintain identical grammatical forms (e.g. running, swimming, and biking).
8. Pronoun-Antecedent Agreement & Ambiguity
Pronouns must match their antecedent in number (singular vs plural). Replace ambiguous pronouns ("they", "it") with specific nouns.
9. Apostrophe Rules (Possession vs Contraction)
Its = possessive ("its tail"). It's = contraction ("it is"). Their = possessive. They're = they are.
10. Verb Tense Consistency
Keep verb tenses consistent with the surrounding passage context unless a time shift word (e.g. "yesterday", "subsequently") dictates a change.
Key Takeaways & Pro Tips
Frequently asked questions
Are commas tested more than semicolons on the SAT?
Yes, comma questions appear roughly 4x more often, but semicolon rules are among the easiest points to secure because they strictly separate two independent clauses.
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