Dialogue moves the story. Without good dialogue you have a page full of letters.
Whatever a character says it has to add to the character and the story in a meaningful way. “The sky sure is blue,” Joe said. If Joe said the sky was blue it better be for a better reason than to take up the readers time. Can Joe say the sky is blue in a meaningless way and get away with it?
Melissa walked out to the pool where Joe sipped a drink staring through his sunglasses at the girls on the other side.
“Don’t you ever get tired of looking?’ Melissa said.
“The sky sure is blue,” Joe said.
Joe avoided the subject, but told us a lot about himself—and it has nothing to do with blue skies.
Dialogue must be real—how people really speak. However whittle away the unnecessary words that slow things down. Everyday conversations are constantly interrupted by things of the moment. For instance, a couple could be driving along and talking about what to do with grandpa’s ashes and a sign says free drink with a meal. “Let’s stop here,” a person might say and what may ensue is a discussion on what to eat and grandpa’s aches might not come up again until dessert. However, this may all occur in your story, but have the discussion about grandpa’s ashes before the blue plate special is ordered.
Let’s hold on for a moment. In the situation mentioned above suppose the discussion about grandpa’s ashes is a difficult one. Here’s a solution;
“Do you know what to do about grandpa’s ashes?”
“No matter what we do, somebody will end up being hurt.”
“Look there! Free drinks with a meal.”
“Let’s get something to eat.”
They stopped into the small diner and ordered the blue plate special. They talked about grandpa’s life, but both purposely avoided the subject of his ashes, however it lurked behind every bite and every word spoken.
This accomplishes everything a writer might want to accomplish in as few words as possible. The reader is not taken down the dark pit of mindless dialogue that actually might occur.
Dialogue has to be sharp and concise. Meaningless expressions and words have to be discarded. Unless you have a character who stutters or is caught in a lie don’t use a collection uhs. Remember, as a writer you are not writing a transcript; leave out the uhs, ums, huhs, and a’s, and the like. However they can be used as effective tools, but used sparingly, like to denote possibly surprise or indifference.
When writing dialogue have in mind that two characters (or more) are speaking. Only one person, the writer, is crafting the dialogue, however each person must not sound like it is coming from the same mind. Give each character different characteristics in their dialogue.
This is just a brief sketch of dialogue. One can write or read a book on it and likely it would pretty much boil down to what is written here.
What is good dialogue? It is nothing more than a well-crafted, believable, and concise conversation that informs and keeps the momentum of the story moving forward.