It helps to think of dialogue as just ordinary conversation – that has a purpose. Monologue is a conversation one has with oneself. Dialogue is a conversation one has with someone else. There are always at leat two people involved in a dialogue.

Your task as a writer is, through the voices having the conversation, to allow your readers to glean more about the characters, their relationships, and their intentions. Sometimes you can also use dialogue to move the action forward, or to reveal something by ‘showing not telling.’

Despite what you’ve been told, eavesdropping is a writer’s most valuable resource. For several days in a row write down a conversation that you overhear, without describing the people who are speaking. Use your ears, not your eyes, to imagine the speaker. Practice trying to remember phrases that are used. As you write them down, try to retain the personality in the words, the flow, and the purpose of the conversation, even if you have to make it up.