1. Separating Items in a List:
* Use commas to separate items in a list of three or more: "I bought apples, oranges, and bananas."
* Use a comma before the conjunction "and" in a list: "She wore a red dress, a black hat, and white shoes."
2. Separating Independent Clauses:
* Use a comma before coordinating conjunctions (for, and, nor, but, or, yet, so) that connect two independent clauses: "The sun was shining, but the wind was cold."
3. Setting Off Introductory Elements:
* Use a comma after introductory phrases or clauses: "After the storm, the sky cleared." "Because I was tired, I went to bed early."
4. Setting Off Nonessential Phrases and Clauses:
* Use commas to set off phrases or clauses that are not essential to the meaning of the sentence: "The book, which I read last week, was very interesting."
5. Setting Off Appositives:
* Use commas to set off appositives, which are words or phrases that rename or explain a noun: "My sister, Sarah, is a doctor."
6. Setting Off Interjections and Parentheticals:
* Use commas to set off interjections (words expressing emotion) and parentheticals (phrases that interrupt the flow of the sentence): "Wow, that was amazing!" "The dog, as usual, was very excited."
7. Separating Dates, Addresses, and Numbers:
* Use commas to separate the day, month, and year in a date: "July 4, 1776."
* Use commas to separate parts of an address: "123 Main Street, Anytown, CA 12345."
* Use commas to separate large numbers into groups of three digits: "1,000,000."
Important Note: The use of commas can be tricky, and there are some exceptions to these rules. It's always a good idea to consult a grammar guide or style manual for further guidance.