The Editor’s Manual
Free learning resource on English grammar, punctuation, usage, and style.
Use “both” to refer to two people or things. “Both” and “both of” can sometimes be used interchangeably, but not always. Use parallel structure with “both–and.” No commas are needed around “both.”
Use “either-or” to affirm the one or the other of two alternatives and “neither-nor” to negate them both simultaneously. Make sure that the elements joined using “or” and “nor” are grammatically balanced and parallel in structure.