I am reading a book about writing. I am not going to mention its name because I don't think it's very good (the writer keeps quoting his own works of fiction to illustrate his point and they really do not inspire me, if you know what I mean). However, he does quote some good people and the chapters on dialogue got me actually thinking about dialogue.
Usually, I don't really think about dialogue, largely because I think I'm better at it than other aspects of writing, so I don't work very hard on it. But these chapters made me THINK. I think I'm going to have to go through my novel once more, looking exclusively at the dialogue, and rewriting it all. (Sigh.)
Anyway, in my attempts to discover how best to write good dialogue, I have done some research and found some good hard and fast rules to stick to when writing the words that people say in your mind.
Only half of your words should be dialogue
I hadn't heard this one before but it does make sense. Essentially, the dialogue to action/thoughts ratio should be no more than 1:1, but preferably lower. I guess if you want it to be higher, you may want to start thinking about writing a script...
Only let one thing happen per paragraph
We all know that when someone stops speaking, and another person starts speaking, we start a new paragraph. However, what I didn't know, but now see in every bit of dialogue I read, is that only one new idea should appear in a paragraph.
So instead of:
'Hi! How are you? What's going on with your hair? Do you think Davey murdered my Granny?'
'Hello! [Answers to the three questions]'
You would have six separate paragraphs where the first person asks one question in each, and the answerer responds to them one by one. It makes things much clearer and advances the plot much more effectively.
Dialogue must always advance the plot
When that one thing is happening per paragraph, something else must be happening. Without everything becoming completely expository, some information must be released to the reader with every line. This doesn't have to be the story, I don't think, it can be character points, but it has to have a purpose.
This holds true of all the words in your fiction, but I think it's worth taking extra care with dialogue. It's very easy to get sidetracked and blown off course when your characters are taking through you. They start having actual conversations like real people. This does not read well.
If you use dialogue tags other than 'say' or 'ask', you are a bad person (or Enid Blyton)
'Goodness me,' exclaimed Judy, 'there's a crab in my bucket!'
'Calm down,' reassured Clive, 'it's a dead crab, the crab in your bucket.'
'But as a child, my beloved hamster Muffy was killed by a crab,' exposited Judy.
'You're a ridiculous person,' grumbled Clive.
Even though it is quite fun to write like that, adding anything other than 'said' or 'asked' does sound a little parodic. According to Elmore Leonard, it also draws too much attention to the writer, and detracts from the story.
It also doesn't work if you add an adverb to the word 'said'; that's just the same thing. So, using the above example:
Judy said, exclaimingly.
Clive said, reassuringly.
Judy said, expositorily.
Clive said, grumblingly.
I realise that these sound wrong largely because those adverbs are mostly of my invention, but even if you might want to use real words, a 'said'-aligned adverb something you should avoid. Trust that the character's actions and the actual dialogue can convey the tone.
And these are the only four definites that I will give you, the rest is about you and yoru characters and how they want to say things. There are layout concerns, obviously, but those can easily be dealt with when you've done the writing.