depends on who directs it and produces it... it's up to the producer and the people who pick the actors but there is no reason why a writer can't act as well.
I believe someone must write the screenplay for it to become a movie.
You can do anything you like after you write a screenplay.
Write a screenplay.... Then shop it....
Yes Melissa did write the screenplay for Twilight:D
George A. Romero wrote the screenplay but King previously published the stories as short stories.
You should not write a screenplay like you would write a novel, or an essay, or newspaper column or any other writing. A screenplay follows a rigorous format and tells a story.
Jodi Picoult wrote the novel "My Sister's Keeper" on which the movie is based. However, she was not involved in writing the screenplay for the film adaptation.
A screenplay is a product. It tells a story. You can write the story as a pitch, as a treatment, as a novel or as a screenplay. Both are required in order to tell your story on film.
The screenplay was written shortly before the movie was shot.
You do indeed need permission to write an adapted screenplay. This is to make sure you are following the copy rights.
He or she writes the screenplay for the movie... Obviously...
Melissa Rosenberg IN FACT DID WRITE THE SCREEN PLAY FOR THE MOVIE BUT NOT FOR THE BOOK..-ROSA REYES