Study Guide

Punctuation

Punctuation questions test commas, apostrophes, colons, semicolons, dashes, and periods. The SAT tests whether punctuation is necessary, unnecessary, or wrong in context.

Key Rules

Commas are needed: before FANBOYS joining independent clauses, after introductory phrases, around non-restrictive (removable) clauses.
Commas are NOT needed: between a subject and verb, between a verb and its object, or inside a restrictive clause.
Apostrophes show possession (the dog's bone) or contractions (it's = it is). Never use apostrophes for simple plurals.
Colons introduce a list, explanation, or elaboration — what comes before a colon must be a complete sentence.
Dashes can replace commas, colons, or parentheses for emphasis — they set off additional information more forcefully.

Common Mistakes to Avoid

Putting a comma between the subject and verb: "The tall student, passed the test." — wrong.
Confusing "it's" (it is) with "its" (possessive). "Its" never gets an apostrophe.
Using a comma instead of a semicolon before "however" or "therefore" in compound sentences.
Adding unnecessary commas after short prepositional phrases: "In the morning, she woke up." — the comma is optional and often wrong here.

SAT Strategy Tips

→For every comma in an answer choice, ask: "Why is this comma here?" If you can't justify it, it's probably wrong.
→Test apostrophes: say the full phrase out loud. "It is raining" = "It's raining." "Belonging to it" = "its" (no apostrophe).
→The "no punctuation" option is often correct — the SAT loves testing over-punctuation.
→If a clause can be removed without changing the main meaning → it needs commas around it (non-restrictive).

Example Question

The ancient ruins, which were discovered in 1987, _______ visited by thousands of tourists each year.

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