SAT Writing · 8 min read · Published December 28, 2025

    SAT Grammar: Commas, Semicolons, and Colons

    The punctuation rules tested on every Digital SAT, with the exact patterns College Board uses.

    The Core Rules

    These three marks drive most SAT punctuation questions.

    • Comma + FANBOYS to join two independent clauses.
    • Semicolon to join two independent clauses without a conjunction.
    • Colon to introduce a list, definition, or elaboration after an independent clause.
    • Em dash pairs to insert extra information mid-sentence.
    • Single comma to set off introductory or non-essential elements.

    The Independent Clause Test

    Before picking any punctuation, check both sides of the mark. If both sides are complete sentences, you need a semicolon, period, or comma + FANBOYS. If only one side is complete, most punctuation marks won't fit.

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