Punctuation: The Basics

SAT punctuation questions really ask one thing: where does one sentence stop and the next one start?

A clause is a group of words with a subject and a verb. A clause that can stand alone is independent. "The bus was late" is independent.

Two independent clauses cannot be joined by a comma alone. That mistake is a comma splice. Fix it three ways: a period, a semicolon, or a comma plus a FANBOYS word (for, and, nor, but, or, yet, so).

Three more patterns show up often. Put a comma after an opening phrase: Before the game, we ate pizza. Put a complete sentence before any colon: I packed three things: a hat, a map, and water. When extra information sits in the middle, use the same mark on both sides: My uncle, who lives in Texas, sends postcards.