The most common mistake of novice screenplays is that they provide exposition mostly through dialogue. This creates two problems. First, listening to information is passive and boring. You typically have to repeat information two or three times before people remember it so dumping exposition in dialogue is usually wasted. That’s because screenwriters look at their exposition as text that you can read, but audiences can’t read the screenplay. As a result, exposition in dialogue is simply forgotten in the audience’s mind.
Second, slipping exposition into dialogue creates awkward conversations like this:
BOB: Hey Jane. I know we’ve been married for five years and have ben having problems lately after my affair, but what do you say we take a trip to the Bahamas since you loved going there the last time we went on our honeymoon?
JANE: I’d love that! I know you’ve been working overtime at General Electric and your boss, Michael, needs to give you a break once in a while because he’s an alcoholic and his wife left him three years ago because she couldn’t put up with his mother interfering in their lives all the time.
Obviously this conversation is an exaggeration but not by much. When characters say information to each other than they already know, it’s obvious this information is for the benefit of the audience. Besides being dense and dull, this information is easily forgotten because it’s so dense and dull. That essentially renders it pointless.
Even worse, when characters speak like this, they aren’t doing anything but talking, creating a “talking heads” scene where nothing is happening. That’s visually boring and remember, movies are a visual medium.
A far better solution is to think visually and try to convey as much information as possible through action without dialogue. Then slip in an occasional nugget of information in dialogue if you must.
Watch silent movies such as the old movies or even recent ones such as “The Artist.” Silent movies let you follow the story through visual actions alone. Then notice when characters, speak, the dialogue actually interferes with the story because it displays a chunk of text on the screen and remains there long enough for everyone to read it.
That’s what dialogue does in talking movies as well. Unless done well and integrated with the action, dialogue can be mostly distracting, especially if you overload it with exposition.
So when writing any scene, think visually and try to get as much exposition revealed through actions alone. Then add dialogue like adding salt and pepper to a main dish. Just as nobody would eat just salt and pepper, so nobody should watch a movie that dumps exposition through dialogue alone.