1. Separating Items in a List:
* Use a comma to separate items in a list of three or more:
* "I bought apples, oranges, bananas, and grapes."
* Put a comma before the conjunction (and, or, but) in a list of two items:
* "I went to the store, but I forgot my wallet."
2. Setting Off Introductory Elements:
* Use a comma after an introductory phrase or clause:
* "After the rain stopped, we went for a walk."
* "Because I was tired, I went to bed early."
3. Setting Off Non-Essential Phrases or Clauses:
* Use commas to set off words, phrases, or clauses that provide additional information but are not essential to the sentence's meaning:
* "My friend, who lives in New York, is visiting next week."
* "The house, painted a bright yellow, stood out on the street."
4. Separating Independent Clauses:
* Use a comma before conjunctions like "and," "but," "or," "nor," "for," "yet," and "so" when joining two independent clauses:
* "I went to the party, but I didn't stay long."
* "She finished her work early, so she went home."
5. Direct Address:
* Use a comma after a direct address:
* "John, please close the door."
* "Mom, can I have a cookie?"
6. Dates and Locations:
* Use commas to separate the parts of a date:
* "The meeting is scheduled for July 4, 2023."
* Use commas to separate the city and state in a location:
* "I live in San Francisco, California."
7. Titles and Degrees:
* Use commas to set off titles and degrees:
* "John Smith, Ph.D., gave a lecture on quantum mechanics."
* "The author, Jane Doe, won an award for her latest novel."
8. Interjections:
* Use commas to set off interjections:
* "Wow, that's amazing!"
* "Oh, no, I forgot my keys!"
9. Clarity and Prevention of Misreading:
* Use commas when necessary to prevent misreading or confusion:
* "I saw the man, running." (Without the comma, it could be read as "I saw the man running.")
Remember: There are some exceptions and nuances to these rules. If you are unsure about comma usage, it's always a good idea to consult a grammar guide or style manual.