1. When "both" is followed by a coordinating conjunction (and, or, but):
* No comma: When "both" is followed by a coordinating conjunction and a second item, you don't need a comma.
* Example: Both the cat and the dog barked at the mailman.
2. When "both" introduces a list:
* Comma after "both": When "both" is followed by a list of two or more items, you need a comma after "both".
* Example: Both the red car, and the blue one, were parked in the garage.
3. When "both" is followed by a dependent clause:
* Comma after "both": When "both" introduces a dependent clause, you need a comma after "both".
* Example: Both the students who studied hard, and those who didn't, took the exam.
Here's a helpful tip: Think about whether the phrase following "both" could stand alone as a complete sentence. If it can, then you likely need a comma after "both".
Let me know if you have any more questions about commas!