Guest Post: Charity Bradford on Punctuation

Thanks Jen for the opportunity to guest post. It's made me look some stuff up that I've been putting off for too long.
How the heck do you punctuate dialogue?
That's a question I'm frequently asking myself. I decided it was high time to educate myself on the rules. This post will not be "fun" to read, but I hope it will help answer some of your questions as well.
Here are some quick basics that I think we all get right. But just in case...

Commas, Periods, Question Marks, and Exclamation Marks

A comma separates dialogue from its dialogue tag. Periods and commas ALWAYS go inside the quotation marks. Question and exclamation marks go inside the quotation marks if they apply to the dialogue, outside if doesn't have anything to do with the material quoted.
Incorrect: "It's a lovely day", Charity said.
Correct: "It's a lovely day," Charity said.
Incorrect: "I think we should go for a walk". Charity up her sweater and walked to the door.
Correct: "I think we should go for a walk." Charity picked up her sweater...
What if the dialogue tag comes in the middle of the talking? Place a second comma after the tag, and after any words that come between the tag and the continuation of the sentence.
Incorrect: "If you want," he said his smile persuasive. "They can find a place for us to stay."
Correct: "If you want," he said, his smile persuasive, "they can find a place for us to stay."
This is the one I mess up all the time--
If a character takes action after speaking, that action usually begins a new sentence and should not be punctuated with a comma, as if it is a dialogue tag.
Incorrect: "We need to leave in case someone comes back," Landry took Talia's hand and helped her up.
Correct: "We need to leave in case someone comes back." Landry took Talia's...

Dashes and Ellipses

Dashes indicate where a sentence breaks off. For example, when one character interrupts another. Ellipses indicate that the dialogue trails off. The fade out if you will due to uncertainty or a reluctance to finish the sentence.
Incorrect: "I never got a chance to tell you . . ."
"Shh," he placed a finger on her lips. "You don’t have to say anything."
Correct: "I never got a chance to tell you—"
"Shh." He placed a finger on her lips, "You don't have to say anything. I already know..."
(That last one is questionable on the ellipses. In my mind that's where he bends to kiss her--so the ellipses.)
Keep each characters' response and descriptive material with his or her dialogue.
Incorrect:
His eyes dropped to her chest, lingered there, and then moved back up to her face.
"Pretty locket."
What nerve! He had deliberately stared at her breasts. Her voice took on a frostier edge.
"Is there something I can do for you?"
Correct:
His eyes dropped to her chest, lingered there, and then moved back up to her face. "Pretty locket."
What nerve! He had deliberately stared at her breasts. Her voice took on a frostier edge. "Is there something I can do for you?"

See how much clearer that is? You don't have to pause and figure out who is speaking. (example from How to Punctuate Dialogue Correctly.)

Here's some more basic stuff.

Capitalization

The first word of dialogue is always capitalized.
Incorrect: She asked, "when will we get there?"
Correct: She asked, "When will we get there?"
When dialogue is divided by a speaker attribution, begin the second half of the sentence with a lowercase letter, not an uppercase one.
Incorrect: "We can be there by morning," he said, "If we get started right away."
Correct: "We can be there by morning," he said, "if we get started right away."
And finally, the all important question of more than one paragraph of one person's dialogue.
When a character has more than one paragraph of dialogue, use closing quotation marks at the end of the final paragraph in the sequence only. Start each new paragraph of continuous dialogue by one character with quotation marks.
Incorrect: "(large chunk of text) We do not detect any plant or animal life on the surface, but we believe that if we heat up the core of the moon we can catalyze the terraforming process."
“As we heat the core, the polar ice caps will melt, providing the liquid water needed to increase the thickness and quality of the atmosphere."
Correct: "(large chunk of text) We do not detect any plant or animal life on the surface, but we believe that if we heat up the core of the moon we can catalyze the terraforming process.
“As we heat the core, the polar ice caps will melt, providing the liquid water needed to increase the thickness and quality of the atmosphere."
Well, there you go. Some of the most common mistakes we (read me) might make when writing dialogue. I hope some of it was helpful. Good luck and happy writing!
Links used while writing this post:
Punctuating Dialogue from Writing World. The easiest to read.
How to Punctuate Dialogue Correctly I used a lot of their example formats.
Punctuating Dialogue
Punctuation in Dialogue from The Editor's Blog

Charity Bradford blogs at Charity's Writing Journey and co-hosts a critique blog called Unicorn Bell. She writes science fiction and fantasy.