Show... don't tell your character arc...
I read this all the time in screenwriting books - a screenwriter should SHOW not TELL a story; but what does it really mean?
Next to ‘write what you know’ show don’t tell is one of the oldest pieces of advice in screenwriting; and rightly so! Screenwriting is a visual medium, we’re creating pictures with words to tell our story. That eventual translation to film is what makes screenwriting so tricky and interesting. If it were only going to remain as words, it would be a novella or a short story.
So the first thing you need to do is figure out what your character’s is feeling in every single scene in which they participate in your story. And then you need to figure out an action - that is true to your character, that shows or telegraphs that feeling. This can sometimes be hard to do. Let’s try one simple, basic emotion on for size and see what happens.
Anger is a really basic emotion but everyone presents or displays their anger in a different way. One character might blow up, lose his or her cool, or clobber someone -- you get the picture. But these actions are very basic, and if you choose them - you create a very basic character with not much range.
Now, what if instead of blowing up when provoked to anger - your character cries? How does that change our understanding of who your character is? Does it make your character more childlike, more female - or does it change the quality of the emotion? Is it not really anger now - but more like frustration that your character is displaying?
Are you starting to get the picture? You’re basic emotion that your character is FEELING is conveyed to the AUDIENCE through ACTION. That is how we read what is going on inside your character. Then the actor gets involved and adds all kinds of nuance or subtleties to your character. She decides that your character blows up, as you’ve written her - but then gets the shakes afterwards. How does that embellish our understanding of what the character is feeling? It certainly adds a new dimension to the basic emotion of anger, doesn’t it? Showing to us the characters internal world.
I hope that helps. And I wish you good luck with your writing.