INT. INKWELL EXAMPLE, DAY
Man, what an action slug we have here. Dialogue begins with an all-caps name and something to say, and scene headers like the one above start with INT. or EXT., (or with something else, just put a period before the name). Anything else is considered an action slug, like this one.
READER Hey, what about me?
BEN SCOTT Oh, hello! You’re a character, aren’t you?
READER Yeah, I sure am! And this is dialogue, huh?
BEN SCOTT That’s right!