Apparently a lot of people get dialogue punctuation wrong despite having an otherwise solid grasp of grammar, possibly because they’re used to writing essays rather than prose. I don’t wanna be the asshole who complains about writing errors and then doesn’t offer to help, so here are the basics summarized as simply as I could manage on my phone (“dialogue tag” just refers to phrases like “he said,” “she whispered,” “they asked”):
“For most dialogue, use a comma after the sentence and don’t capitalize the next word after the quotation mark,” she said.
“But what if you’re using a question mark rather than a period?” they asked.
“When using a dialogue tag, you never capitalize the word after the quotation mark unless it’s a proper noun!” she snapped.
“When breaking up a single sentence with a dialogue tag,” she said, “use commas.”
“This is a single sentence,” she said. “Now, this is a second stand-alone sentence, so there’s no comma after ‘she said.’”
“There’s no dialogue tag after this sentence, so end it with a period rather than a comma.” She frowned, suddenly concerned that the entire post was as unasked for as it was sanctimonious.
And!
“If you’re breaking dialogue up with an action tag”—she waves her hands back and forth—”the dashes go outside the quotation marks.”
