Many beginner writers struggle to get dialogue punctuation right, so I thought I would copy some paragraphs from The Writer’s ABC Checklist to give a few pointers on punctuation for dialogue.
When the dialogue tag forms part of a sentence, you should use a comma after the speech, close the quote marks, and use a lower case letter for the tag.
“You drove me to it,” he said.
Notice that in the examples below a lower case letter is used even when it follows a question mark or exclamation mark. This is because the tag is part of the sentence, not separate to it.
“How could you?” she asked.
“You’re an idiot!” he yelled.
“You’re an idiot!” he yelled.
However, when no tag follows the dialogue you should use a full stop, question mark or exclamation mark to finish the speech and then close the quote marks.
“How could you?”
“Easily, you drove me to it.”
“You’re an idiot!”
“Easily, you drove me to it.”
“You’re an idiot!”
When dialogue continues after the tag, but is still part of the same sentence, a comma is used, with a lower case letter starting the next section of dialogue.
“There are times,” she said, “when I could murder you.”
When dialogue continues after the tag, but is NOT part of the same sentence, a full stop is used, with a capital letter starting the next section of dialogue.
“I don’t understand you,” he said. “What on earth did you think you were doing?”