It is important to remember the difference between real life conversations and structured dialogue. Characters are made up of what they do and what they say. Dialogue should always be “functional” meaning that it pushes the story forward, makes a statement, incites comedy, or all of the above.
Make sure not to make your dialogue “on the nose” people don’t always say what they mean, and they don’t always mean what they say. This is called subtext. Writing between the lines if you will – when characters are talking about one thing yet are saying something completely different. The balcony scene in Woody Allen’s Annie Hall is a great example of subtext. Annie Hall – Balcony Scene
Keep it snappy. Try and limit lines of dialogue to 1 to 3 lines.
INT. BAR – NIGHT
Mark and Dane finish putting caution tape on the bathroom door.
Perfect. Then we’ll just let Cici clean it when she gets here.
Sounds like a plan.
It’s not, but it sounds like one.
Do you feel like there’s someone behind us?
Like standing right behind us?
Yeah, we should turn around.
A gravelly voice interrupts.
Get me a whiskey sour!
They turn to see a man that looks vaguely like Santa Clause, SANTA, sitting at the bar. His scowl could murder a Russian bear.
If it’s not snappy make sure that long speeches or monologues are at the very least an embodiment of all the above, memorable and quotable. They must have momentum and make a meaningful impact on the story.
INT. DETECTIVE OFFICE – NIGHT
THUNDER ROLLS outside.
DAVID sits in an old leather spinning chair drinking scotch. The office is dark and drab. Another chair sits opposite David at the old oak desk. Black and white pictures adorn the walls.
The office door reads, “EARL JONES DETECTIVE AGENCY”.
The old man left everything to me. I mean it wasn’t much, but it was better than my digs. But nobody would kill for this dump, the cops knew that. Scotch though, the old man would have killed for his scotch.
Startled, David swings his chair around.
*Hint: Cast your characters in your mind with people you know or your ideal actors, it can really help in the fluidity of dialogue and pushing scenes forward.