How do you go about determining what your characters' idioms and syntax will be in dialogue (if you are using a real-life setting)? Talking with people similar to your characters and reading books with characters similar to your own has been common advice, but I was wondering if others do any other type of additional research? If so, what sources do you tend to use?
Earwigging. Listening to street gossip, conversations in queues, on buses and in cafes. Write down what you can, as you can.
Peoplewatching, stealing from real people - or I'm a research junkie so I'll boil it back to where and how the character grew up and look up the local dialect. I'm working now on trying to pepper one character's dialogue with California-specific idioms so I'm purposefully including words like "hella" where I normally wouldn't. It's also fun to make up idioms out of the characters' experience. I've got one character who grew up as the youngest child of a family who owned a diner, so I have all of her immediate family refer to her as "Short Stack" (as in pancakes). I have another guy who is a war correspondent for a news network and him I have use a lot of obscure war analogies from random places he's been (he once described something as "drier than a muzzle barrel in the Karakalpakstan desert" - which makes him look weird and pretentious to both the reader and the other characters).
