Dialogue Punctuation

This is only semi-related, but it's priceless.

Dialogue loves to confuse writers and make them want to bash their heads against the wall. There are so many rules, and some don't even make sense.  Well, bash no more, because I shall (at least try to) explain.

A dialogue tag is a set of words placed directly before or after dialogue. He said, she said, I yelled, and so on. If you've got just a piece of dialogue with a tag, it'll look like this:
"I just went to the store," he said.

Let's look at that again.
Wrong:
"I just went to the store." He said.
"I just went to the store," He said.

Right:
"I just went to the store," he said.
Note the comma and lowercase h. Never use a period before a dialogue tag. Always use a comma, and never capitalize the next word unless it's I or a name.

Wrong:
"Did you buy me anything," she asked.

Right:
"Did you buy me anything?" she asked.
This is a question mark, so don't use a comma. Don't use one instead of an exclamation point, either.

Wrong:
"No," he replied. "But I knew I was forgetting something."

Right:
"No," he replied, "but I knew I was forgetting something."
Since No, but I knew I was forgetting something. is actually one sentence, you use a comma before the tag, and a comma after the tag.

Wrong:
"Aww," Susie pouted.

Right:
"Aww." Susie pouted.
There's no comma here, since Susie pouted. isn't a dialogue tag. It's simply stating an action. You can't pout a word, can you?

Wrong:
"How did you do that" he asked.
"I talked to him yesterday" he said.

Right:
"How did you do that?" he asked.
"I talked to him yesterday," he said.
You always need puncuation with your dialogue.

Wrong:
"Hey, that was funny," I laughed.

You can't laugh a word. You can't smile it either, and if you hiss it, it'd better have an s unless you speak Parseltongue.

Right:
"Hey, that was funny." I laughed.
I laughed isn't a tag, it's just a sentence.

Wrong:
"Hello everyone" he said.
"Hello everyone", he said.

Right:
"Hello everyone," he said.
You always, always, always need punctuation inside your quotes. Always. I can't think of a reason you wouldn't.

Wrong:
"Billy, did you do your homework?" the teacher asked. "No, my dog ate it," Billy replied.

Right:
"Billy, did you do your homework?" the teacher asked.
"No, my dog ate it," Billy replied.
Always, always, always start a new line for each new speaker.

I don't know why the rules are so confusing. I didn't write them. Yes, I know they don't make sense. You just have to learn to deal with it.

I hope that helped. Since I probably forgot something (or quite a few things), there's also a really great article here. The best way to learn all these rules is simply to read a lot of books. Books have a lot of dialogue, and hopefully you'll learn how it works as you read. Pay close attention, and watch where punctuation is placed in different situations. If you have any questions, feel free to ask me!

Originally posted here.