As some of you (I hope) know, dialogue is set off by punctuation known as quotation marks. The quotation marks go only around the part of the sentence that's spoken by a character. In America, quotation marks around dialogue are doubled:
"Hi! I'm Harmony Khaerrysma Mary-Sue Fluffybunny Greenberg!" said the young witchcraft student.
But in England, they're single:
'I know,' said Herbert, the crotchety old wizard. 'Kindly remove yourself from my presence.'
I'm going to use the American version throughout the rest of this piece because, well, I'm American and if I try single quotes I'll screw up.
Most dialogue has a dialogue tag attached to it. That's the bit that goes "he said" or "she said." Dialogue tags can come before, after, or even in the middle of sentences of dialogue.
Harmony said, "But I'm sweet and happy and I can turn into a tame Dragon."
Herbert said, "Good for you."
When you use a dialogue tag after a sentence, the period that would normally go at the end of the dialogue is replaced by a comma, so that your reader knows there's a tag coming afterwards. If the sentence of dialogue ends with another kind of punctuation, such as a question mark or an exclamation point, don't replace it with a comma; leave it as it is. Also, be sure to put unusual punctuation marks in the dialogue itself, and not after the tag.
"I'm so glad you think so," Harmony sparkled.
"Were you going somewhere?" asked Herbert.
NOT: "Were you going somewhere," asked Herbert? That implies that you're unsure whether Herbert asked, and that Herbert wasn't really asking at all, but stating.
Notice the difference in capitalization. If you start the sentence with a tag, the dialogue is still capitalized; if you start the sentence with the dialogue, the tag is not capitalized. Also notice that it doesn't matter if you put "said" or the speaker first. (It's conventional to put the speaker first if your tag comes before the dialogue, but putting the speaker second in this case is not technically wrong.)
A dialogue tag in the middle of a sentence is a good way to vary sentence structure and keep your reader entertained. When you do this, you should put the dialogue tag at a place in the sentence where there would already be a comma. Put a comma in, close the quotation marks, write your dialogue tag followed by a comma, and then put another quotation mark and start your sentence again--but don't capitalize that next half of the sentence.
"Well," said Harmony, "I wasn't really planning on it..."
"If you need help getting to your dormitory," Herbert continued, "one of my students would be happy to show you."
"You know, Herbert," Harmony said, "I really enjoy talking to you."
Let me reiterate: If your dialogue is followed by a dialogue tag, do NOT end that dialogue with a period. It's one of the most common errors among people unfamiliar with dialogue, and it's one of the easiest to fix.
On the other hand, even published authors get away with the next problem...
Dialogue tags are not a way to join sentences of dialogue together. They may come before or after a sentence, but not both without some kind of period. Note that not every sentence must have a dialogue tag; they can be omitted if it's clear who is speaking.
"I can't say the same about you," Herbert said. "And that's Professor Herbert."
I'd recommend against doing something like this: "I can't say the same about you." Herbert said, "And that's Professor Herbert." It's not wrong, punctuation-wise, but it sounds like you're emphasizing that Herbert said the second part, which always makes me wonder who said the first part.
It's perfectly legal to use a dialogue tag on one sentence, but have more than one sentence between those same quotation marks. Note that you only replace the last period with a comma, not any of the others.
"But, Herbert, I'm your biggest fan! I've read about all your magickal discoveries! I came to this school especially to work with you. Please, just speak with me for a little while," Harmony pleaded.
Finally, if you have more than one paragraph in a row spoken by the same person, you donêt close the quotation marks on any paragraph except the last--but you still start every paragraph with a quotation mark.
"I know what it must be like to have to deal with difficult magick every day as you do for your research, but you could come home to me to relax and unwind!" Harmony said. "I can cook your meals, massage your feet! I could make your cold, dank chambers a home!
"We'd have such a wonderful life together, Herbert. Won't you at least consider it?"
Every time you start a new speaker, you should start a new paragraph. It helps keep things clear for your reader and helps you keep track of the flow of the conversation.
When Herbert didn't answer, Harmony began to plead. "We could keep bunnies and kittens and puppies! And while you deal with your colleagues, skewering them with your scathing wit, I could stay in your rooms and make tea! We could make Sweet Tender Love every night and exchange Words of Endearment during the day! And as a tame Dragon shapeshifter, I have special Shields that will protect you from the Evil of your Noble Work!"
"Is there a reason you're capitalizing all your words?" Herbert said. "And anyway, I'm in love with Professor Janice, the dwarf."
While Harmony's mouth worked silently, Herbert turned on his heel and left.
There are two things you should keep in mind for long sections of dialogue: you want your reader to focus on the words of your characters, and you don't want your reader confused. Basically, that means you should find a compromise between avoiding tags entirely and putting a tag on every line.
Actions are a good way to break things up, since most people don't like long sections of pure dialogue; for novels, you may want to be especially sure to use tags or action on nearly every line, as that's the kind of detail novel readers expect. They also have the advantage of letting your reader know who's speaking without having to say "said" on every line.
You want your reader to forget you're even including dialogue tags. Readers' eyes will skip the word "said" as long as you don't put it every line; "asked" with questions achieves the same effect, although not as well. My examples above include a lot of words which are not said (sparkled, continued, pleaded)...which makes me a bad person, and you should feel free to spork me for it. Anyway, those words should be saved for the times when they are absolutely necessary. 'Overuse' to some of my editors is six or seven times in a 4,000-word story that is almost pure dialogue, just as an example.
You've probably had writing teachers tell you to vary words, especially to use more active verbs. "Crept" is a lot more active than "went quietly," for example. So you may be asking, "Why don't we do the same thing for dialogue?" Simply put, in action, the verb carries the meaning; in dialogue, the words the characters speak (and not the manner of speech) carry the meaning. You want your reader to ignore the how and pay attention to the what.
Now, we come to the bane of many a writer's existence: the adverb with a dialogue tag. I'm guilty of this too, so insert pot-kettle phrase here, but I know I'm supposed to watch out for it (even if I don't). Adverbs, if you're not familiar with the term, are like adjectives (describing words) except that they modify verbs or other adjectives or adverbs. You can usually find them by looking for words that end in -ly: quickly, harshly, needlessly.
The adverb with dialogue is like this:
"You're out of tune!" the choir director told her class sharply.
"I'm really at the end of my patience," the dwarf said shortly.
Note that within dialogue, adverbs are permissible (within reason) because that's the way people speak; it's only when you're describing the dialogue or other actions that they become a problem.
Adverbs aren't grammatically incorrect, of course, but most writers that I know try to keep them to a bare minimum. Why? Besides the opportunity for horrible puns, adverbs are like waving a big red flag at your reader and shouting, "I don't have confidence in my dialogue, so I want to make sure you can hear the tone of voice." If your dialogue is true to the characters and the situation, tone of voice should be clear and you don't need an adverb with the tag at all. Adverbs may seem like a short cut; for example, you could say "quietly" instead of describing how a formerly angry character comes to understand why she's wrong and as a result calms down. That description is a lot more valuable and true to your reader than any adverb, though.
In summary: The mechanics of dialogue follow a few simple rules, and they're not hard to follow. Dialogue is one of the places a lot of new writers make mistakes--keep your punctuation clean and correct, and you've already given yourself an advantage.
By Melanie Simet (email: mel@world-building.net), revised 09/2005. Released under a Creative Commons Attribution-NonCommercial-NoDerivs 2.5 License.