The Five Comma Rules You Need to Know

Rule 1: Independent Clauses Joined by FANBOYS

When two independent clauses are joined by for, and, nor, but, or, yet, or so, place a comma before the conjunction. "I went to the store, and I bought milk."

Rule 2: Items in a List

Use commas to separate items in a list of three or more. The Oxford comma (before the final "and") is preferred on the ACT but not strictly required. "Apples, oranges, and pears."

Rule 3: Nonessential Modifiers

Set off nonessential phrases with paired commas — one before, one after. If you can remove the phrase and the sentence still identifies the same noun, the phrase is nonessential. "My brother, who lives in Toronto, is visiting."

Rule 4: Introductory Elements

After an introductory phrase or clause, use a comma. "After the meeting, we went to lunch."

Rule 5: Coordinate Adjectives

When two adjectives independently modify the same noun, separate them with a comma. "A tall, ancient oak tree." (Test: can you swap their order or insert "and" between them?)

What to do next

Drill comma punctuation questions until you can name the rule for every correct answer.