In real life, we don’t always speak in complete sentences, we often use contractions, and we drop letters at the end of words. We blend together two words, such as going to and should have. We don’t address the one being spoken to by name every time we say something to her. And we don’t always respond to the question or statement being posed.
In your stories, characters should speak the way the real people do, in fits and stutters, each having his/her own agenda in terms of what he/she wants to get out of the conversation.
For example, the girl wants the boy to ask her to the dance; the boy wants to get a kiss. The teacher is chastising a student for missed work; the student just wants to get out of the room.
Dialogue should not be used to lecture the reader on background information. For example, for a story set in San Francisco, the reader assumes that both speakers are familiar enough with the city that talking about its history would never come up in casual conversation. Unless one of the speakers is a professor taking his students out on a walking field trip.
The word said is good enough as an attribute. Don’t go searching for clever alternates such as guffawed, chortled, replied or exclaimed. In a back and forth conversation between two speakers, each line does not have to end with said.
“I’m going to New York for vacation,” Mary said.
“I’ve been thinking about going to Paris,” Bob said.
“I went there last summer.”
“Did you like it?”
Because of the nature of dialogue, combined with new lines for each speaker, the reader knows that Mary visited Paris and that Bob wants to know what she thought of the city.
Your task to find a piece of your writing and locate dialogue. Reread it. Is it natural? Is there a flow to the conversation? Can you imagine two people standing in line at a coffee shop saying the words? If not, then rewrite, aiming to make the language realistic sounding.
Does each character have an agenda? If not, give them one.
Look for attributes. Is there an over usage of alternates to said? If so, rewrite and eliminate all those that impede the flow of the dialogue.
When you are finished, reread the new version. Is there a more natural flow? Does it seem more realistic?