When should a comma be used before a quotation?

A comma should be used before a direct quote to indicate that the speaker's exact words are about to follow. This punctuation helps to clarify that the dialogue or statement that comes next is not a part of the narrator's own words but rather a direct reproduction of someone else's speech or thoughts. For instance, in a sentence like, "She said, 'I will be late,'" the comma serves as a clear transition from the speaker's attribution to the quotation itself.

This use of the comma enhances readability and provides a clear structure to the sentence, signaling to the reader that a distinct voice or perspective will follow. It's important to distinguish this use of the comma from its applications in other contexts, such as separating independent clauses or positioning after a quotation, where the comma serves different grammatical purposes.