1. When "both" is followed by a list:
* No comma: If "both" introduces a list of two items, a comma is not needed:
* _"I like both apples and oranges."_
* Comma: If "both" introduces a list of more than two items, a comma is needed after "both" to separate it from the list:
* _"I like both apples, oranges, and bananas."_
2. When "both" is part of a longer phrase:
* Comma: If "both" is part of a phrase that acts as an introductory element, a comma is needed after the phrase:
* _"Both, in my opinion, are good choices."_
* _"Both of them, however, have some drawbacks."_
3. When "both" is used for emphasis:
* Comma: A comma may be used after "both" for emphasis, even if it's not followed by a list:
* _"Both, I assure you, are true."_
In summary:
* Use a comma after "both" if it introduces a list of more than two items or is part of an introductory phrase.
* Don't use a comma after "both" if it introduces a list of two items.
* Consider using a comma for emphasis, even without a list.