Common Uses for Commas Introductory Clause: Rule: Example: Explanation: a fragment (it cannot stand along as a Use a comma after most introductory Although the door was locked, In the example, the italicized section is sentence) that introduces the main clauses that are longer than two someone broke in and took a the introductory clause. Notice that the idea. words. shower in our house. comma follows the introductory clause to separate it from the main sentence. Transitional Expression: Rule: Examples: Explanation: shows how one idea in a sentence If a transitional expression is in the All of my professors are insane. In the examples, the transitional relates to another idea in the same middle of a sentence, set it off with My English professor, for expressions are italicized. In the first sentence or in the sentence directly commas on both sides. If it comes at instance, wears her pet chinchilla example, the transitional expression “for before or after. the beginning or end of a sentene, around her neck during lectures. instance” appears in the middle of a only one comma is necessary to sentence and is set off with commas. In sep[erate it from the rest of the Many offices are observing the second example, the transitional sentence. holiday hours. For example, post expression “For example” appears at the offices and banks are closed beginning of the sentence and is today. therefore followed by a comma. Parenthetical Expression: Rule: Example: Your hair, by the way, Explanation: a word, or group of words, that Use a comma before and after the looks absolutely fabulous. In the example, by the way is a provide relevant but not essential parenthetical expressions. parenthetical expression and is therefore information in the middle of a set off with commas. sentence. You could put parentheses (like this) around the word(s) and the sentence would still make sense. Four other uses for commas: 1. Use a comma after answering a “yes” or “no” question. Yes, I will go to the mall with you. 2. Use a comma after an interjection, such as oh, wow, and ouch Wow, you did great on that essay! 3. Use a comma when directly addressing a specific person. Are you going to the movies with us, Andy? 4. Use a comma to contrast. I want to see the last Twilight movie, not Harry Potter, this weekend. © 2010 Cengage Learning, Inc. All rights reserved.