When a playwright starts working on their play, they might not think about the format first. But once inspiration strikes, the structure of their script is what brings their vision to life on stage.

Maybe you’re thinking about writing a screenplay, but don’t know where to start. Or maybe you’re interested in following in the footsteps of writer-directors such as Mindy Kaling or Jordan Peele.

When I went to the University of Southern California for my MFA in screenwriting, I took a one-hour TV drama course for my thesis. My thesis adviser said there were three types of TV writers: “big ...