Dialogue is not talk.  Talk is what “real” people do.  Dialogue is what “characters” do.  The difference between talk and dialogue is that talk may or may not move a conversation forward while dialogue must always move a conversation forward.  If a writer looks at a short story as a journey for the reader, then dialogue should facilitate this journey as efficiently as possible.

Dialogue must have tension.  Some sort of tension should be at the center of all well written dialogue.  It is only when the characters of a story speak that the conflict is given a human voice.

Good dialogue will project characterization.  Each character in fiction should be individualized even if the character is on stage just for a moment.  One of the easiest ways of doing this is to give each character something to say that only makes sense if that particular character says it.

Good dialogue will have forward movement.  In creating a line of dialogue, the writer should ask, will this line of dialogue move the story toward its final resolution?  Will this line of dialogue give the reader necessary information?

Understory is that part of the story that is left to the reader’s imagination, the part of the story that is implied.  Dialogue is perfect for allowing the reader to “read between the lines.”

Finally, there is backstory.  How did your characters get to where they are in the present?  If you write very short stories like flash fiction or short shorts, the story is simply too short for a flash back.  The best way to hint at the backstory is through the dialogue.  The operative word here is “hint.”  The reader should never feel that the writer is spoon feeding what the characters are saying.

Writing good dialogue is never easy.  Writing great dialogue is even more difficult; but if you keep in mind the five elements of good dialogue that are in this article your story and characters will have a better chance of coming to life in the imagination of the reader.