Commas: When and How to Use Them
| Comma Rule | Example |
|---|---|
| Use a comma to separate two independent clauses when they are joined by one of seven coordinating conjunctions (for, and, nor, but, or, yet, so). | We were out of ice cream, so I went to the store. |
| Use commas around (a) participial phrases, (b) appositives, and (c) adjective clauses. | (a) Joey, moving quickly, left his house and headed to the train station. (b) My English teacher, Ms. Jones, taught the class about commas. (c) Sarah had cereal, which she thinks tastes better, instead of oatmeal. |
| Use a comma after an introductory phrase, clause, or word. | Right before class, I decided to get a snack. Yes, you may come in. |
| Use a comma to seperate a series of three or more items. | His best friends were Nick, Michael, and Sam. |
| Use a comma when introducing a quotation. | J.D. Salinger said, “My name is J.D. Salinger. I wrote books." |
| Use a comma in between contrasting elements. | Her favorite color was blue, not red. |
| Use a comma to indicate a pause to the reader. | His tone seemed upset, almost bitter, over the phone. |
Common Comma Mistakes
Too many commas in a sentence may make your writing clunky and difficult for the reader to follow.
Try to avoid oversaturating your text with commas.
| Mistake to Avoid | Incorrect Example | Corrected Example / Explanation |
|---|---|---|
| DO NOT separate the subject from the verb with a comma. | The scary dog, barked all night long. | The comma incorrectly separates the subject (dog) from the verb (barked). |
| DO NOT use a comma to separate (a) compound subjects or (b) compound verbs. | (a) She, and her friend went to the grocery store. (b) Joey and Michael went to the party, and danced to music. | In (a), the comma incorrectly splits the compound subject. In (b), the comma incorrectly splits the compound verb. |
| AVOID “comma splices”: In order to separate two independent clauses, you should not use a comma unless you also use a coordinating conjunction. | Emma wanted to meet new people, she tried to join more clubs. | Emma wanted to meet new people, so she tried to join more clubs. |
Created by Nate Metz. Published 2021.
