Good dialogue is like music. It has rhythm, melody and a beat. It is sparse, tight, economic and usually no more then 2-3 lines. It has movement. Conveys exchange of power -> sexual, political, and social. It is also loaded with subtext. Everything is implied but not stated. What they really want to say, but hold back. Symbolic.
Dialogue reveals:
1. Gender
2. Age
3. Life Experience - maturity
4. Where a person is from
5. Socio-economical status
6. Level of education/intelligence
7. ATTITUDE!
Bad dialogue is wooden, stilted, and unnatural. All characters sound the same. Too long -> expositional. Has no subtext.
Functions of dialogue:
1. Reveals something about the character - attitude
2. Relevant and necessary to the character, situation, story
3. Impart critical information to another character
4. Moves the story forward