1. Separating Items in a Series:
* Example: I bought apples, oranges, bananas, and grapes at the market.
* Rule: Use commas to separate three or more items in a list. Note: the last comma before the conjunction (and, or, nor) is optional, but its use is becoming more common.
2. Setting Off Introductory Phrases and Clauses:
* Example: After the long drive, we were all exhausted.
* Rule: Use a comma to separate introductory phrases and clauses from the main clause.
3. Separating Independent Clauses:
* Example: The sun was setting, and the birds were singing.
* Rule: Use a comma to separate two independent clauses (clauses that can stand alone as sentences) when joined by a coordinating conjunction (for, and, nor, but, or, yet, so).
4. Setting Off Nonrestrictive Phrases and Clauses:
* Example: My friend, who lives in California, is a surfer.
* Rule: Use commas to set off phrases and clauses that provide additional information but aren't essential to the meaning of the sentence.
5. Setting Off Parentheticals:
* Example: The new restaurant, by the way, has excellent reviews.
* Rule: Use commas to set off words or phrases that interrupt the main flow of the sentence.
6. Separating Dates and Addresses:
* Example: He was born on July 4, 1985, in New York City.
* Rule: Use commas to separate the parts of dates and addresses.
7. After a Salutation in a Letter:
* Example: Dear Sarah,
* Rule: Use a comma after the salutation in a letter.
8. After the Closing in a Letter:
* Example: Sincerely,
* Rule: Use a comma after the closing in a letter.
Remember, these are just the most common uses of commas. There are some exceptions and more complex situations. It's always a good idea to consult a grammar guide or style manual for more detailed information.