Martin McDonagh: Listen to people
"Write down exactly—to a word—how people speak."
Filmmaker Martin McDonagh:
If there’s anything that can teach you to write dialogue, it’s listening to people. That’s one of the most important things…Listen to people, observe people, as opposed to going to the movies and listening to characters. You can sit in a diner or on a bus, or walk down the street and listen, properly, and if possible write down exactly—to a word—how people speak, that can help. I learn by traveling to small-town America and speaking to people. I like to take trains a lot and now and then a bus or two, and I like to go into local restaurants and listen to people. In my daily life, I hardly ever swear, though my characters do quite a lot. But I don’t judge them. A lot of my characters are working class people, and that’s the language that these particular types of working people choose to use. It’s never to deliberately shock; in fact I hardly even notice that there are so many swear words in there until people point them out to me. While traveling, I keep my eyes open for an interesting town or landscape. That’s what happened with ‘In Bruges.’ I like a town to be a character and a backdrop to a story.”
Source: The Best Filmmaking Tips of 2017