On Writing Dialogue
In the genre (type) of fiction referred to as “literary,” it is important of think of dialogue as a special part of the story. In other genres — mystery romance, thriller, etc. — dialogue may be more plentiful or even routine. I have been taught by my most appreciated instructors (in my long past) that dialogue is such an important part of story that it should be reserved for things that must be spoken. In other words, don't waste time on saying hello, goodbye, how are you, and asking routine questions. Handle the minutiae in exposition. Don't use dialogue for “Hello, Sandra. How are you feeling?” I said, and Sandra replied, “I am fine. How are you?” Maybe instead, do that bit of business like this: Sandra and I exchanged greetings and I said, without any preamble, “I suppose you heard that Frank left me.” Sandra looked with revulsion at me and replied, “What did you expect after the way you treated him for all those years?” See how this elevates the scene in a way that is more interesting?
In literary dialogue it is important to remember that in life, people often have their own agendas when they speak to each other. Have you ever been to a party where a circle of people — of perhaps three or more — are talking to each other? Have you noticed that while one man is talking, others are waiting to talk? Sometimes the person will wait their turn or maybe they will interrupt to add relevant or irrelevant information. John says, “So, our little Johnnie got accepted at UCLA.” Linda says, “Grant got accepted there too. And he's on full scholarship.” Or then perhaps Melanie says, “Keith has decided to wait for a year and work before he goes to college.” These responses are on the general topic at least. What if Ross is bored by all this because he has no children. He might say, “Did you try that cheese and broccoli dip? Who made that? It's killer.”
It is very important to consider who is talking to whom. If your character has an overbearing boss who discourages disagreement, the topic(s) of conversation will most likely be driven by the boss. Unless the employee is quite outspoken and independent or has a new job lined up. How your characters talk to one another is determined by their personality, social status, and current agenda or interests.