Screenwriting is all about efficiency. Maximum impact with the minimum number of words.
So one of my biggest pet peeves is when I see the following in scripts:
She shakes her head no.
There are two big things wrong with that action line:
- Why is the word “no” there?! We already know she’s saying “no” because she’s shaking her head. If the audience can figure out what she’s indicating without her actually saying it, there’s no need to give the reader this extra piece of information.
- What’s a “head no”? Even though it’s completely unnecessary, if you’re going to explain what she means by shaking her head, at least put a comma between “head” and “no.” Or better yet, add quotation marks and capitalize the word: She shakes her head, “No.”
But really, this is all you need to write:
She shakes her head.
Similarly, if someone is nodding their agreement, there’s no need to write:
She nods her head, “Yes.”
She nods her head.