the secret to syntax
It's really simple, actually: listen.
If you pay attention to the way people talk, you'll realize that in common interaction, spoken language is nothing like written language. Try taking down sentences you hear word for word, without adding anything. You'll see that lots of stuff is simply left out, without any problems.
What the hell do you want? will often show up as Hell you want? or The hell?
Did you eat yet? as You eat yet?
Your grade school English teachers might object, but the sentence I did not feel like it sounds stilted and forced (which of course may be what your character is feeling, and then it's okay); more likely somebody will say Didn't feel like it.
These are all obvious points of syntax that you can observe, most probably, in your own spoken language. In order to write realistic dialogue of somebody who speaks a variety of English other than your own -- or English as a second language -- you need to watch for patterns of difference. So Candy's example from her comment was interesting:
here are a couple of grammar/syntactical quirks about Chinese (specifically, Hokkien):- We don't conjugate verbs.
- We don't use "to be" before adjectives. Instead of "she's short" or "he's stupid," literal translations of Chinese sentences would read as "she short" or "he stupid." Or, even more literally, "it short" or "it stupid," since our pronouns are not gender-specific.
The dropping of the verb "to be" is a grammatical feature found in a lot of languages. The copula (look at the root of that word, and see if you can figure out the connection) is used where subject and object of the verb are semantically the same, or linked. Susan is a doctor (Susan=doctor) shows up as Susan doctor in a whole variety of languages, and in some varieties of English as well. So if you're writing a character who speaks Hokkien as a native language and learned English later in life, you need to actually listen to such a person to find out what syntactic patterns from the mother tongue have been transferred into their English.
If you look at Peter's short speech again, you'll see lots of syntactic strategies found in a number of varieties of English, including AAVE (African American Vernacular English), for example: I ain't never been call a nigger by no white folks. Multiple negation is the rule rather than the exception in the languages of the world. The more negatives in the sentence, the more forceful the negation (forget the two negatives make a positive thing, which was thought up by some anal retentive schoolteacher in the 1800s; that's not the way language works).What you can do, if you have a character who is a native speaker of a Hokkien or Norwegian or Swahili (or a variety of English other than your own, such as Innisfree or Capetown or Mobile) is find somebody to listen to, and make notes of what strikes you as distinctive.
My husband is a Brit, and I have long lists of things from him. Examples: Are you going to stop at the store? I might do. Do you think I should call them? I should, if I were you. What took so long? We were trying to catch Thor up. How is Jeffrey? He's still in hospital.
Before I go on with this tomorrow, I wanted to point out a few things. First, the most distinctive thing about language is often its rhythm, but prosodic notation just isn't possible in a novel, beyond the occasional use of italics. And second, all of these notes have to do with writing dialogue, and thus with the representation of spoken language. The application of these methods to narrative is a different matter entirely, and I'm not going to go into that here.
Now I have to go write my 5,000 words for the day.