Q. How do you write a montage scene and how can you incorporate dialog during the scene?
Any way you like. There's no canonical way.
You could describe every moment:THE CAR races down the twisting road.
PIGEONS flutter into the sky.
THE KNIFE comes down.
THE BAR PATRONS laugh.
Or you could describe what you want the editor to come up with:SERIES OF QUICK STOCK SHOTS of shells bursting, men screaming, tank wheels rolling, etc.
I generally prefer the first way if I'm writing a selling script; sometimes I use the second if I'm writing a production script. Ultimately a montage is a creation of the editor, so in a production script you can cop out a bit. But for a selling script you want to give the reader something as close as possible to the experience of watching a film, so you write out the montage even though you know the editor will probably do something different (and better).
Personally I don't tend to flag anything as a montage in my screenwriting. I feel it's a bit alienating to the reader to say "hey, lookie, it's a montage!" Just be specific about what exactly you're proposing to put on the screen (even if the director editor will almost certainly do something else), and "montage" and don't call it a montage.
On the other hand, when intercutting between two scenes, I usually don't break the scenes up because it starts it get irritating to read. I'll just put INTERCUT: and hope the reader pays attention to the transitional:
INT. FASHION SHOW MAIN HALL - X COLLECTION - NIGHT
--as Prana struts out on the catwalk in an elaborate evening gown --
the finale of the show. The crowd applauds wildly, and Prana, in the
brilliant lights of the catwalk, smiles like a girl who has everything
in the world she ever wanted, as--
INT. AMBER'S HOSPITAL ROOM - NIGHT
... Amber's watching the fashion show on TV, in her darkened hospital room, her eyes rooted to
That's going to be me. Soon as I get out of here.
It's going to be me.