I don’t know if the characters in Charles Dickens novels talked like actual people in Dickens’s London, but people don’t talk like his characters today, and that is a primary reason not to imitate a period writer. Unless you are writing in that period of course. I have written two novels, one based in 1911 New York, the other in 1922 Los Angeles. One should not assume the English language has not changed. It has. Every era has slang, as well as phrases and words that, for whatever reason, have taken on new meanings decades later. For example the word ‘gay’ in the eras I wrote in had no homosexual connotation. There are also phrases used in the past everyone understood, but today makes no sense to us.
For the 1911 novel I used Irving Lewis Allen’s book “The City in Slang: New York Life and Popular Speech.” For the novel set in 1922 I researched flapper slang and also read and listened to the dialogue of Raymond Chandler, Dashiell Hammett, and watched 1930 and 1940 films, as I wanted that noir sound.
That is where the ear becomes important. If you are writing a contemporary story, characters should talk befitting their profession, class, education, and their social circles. Listen not with your brain to what people around you are saying, but listen with your ear. The tone of the voice, how sentences are strung together-especially if the person is strung out. You never know when you might need a drugged out character.
To oversimplify, if you have seen the TV show, “The Big Bang Theory” you know Penny is a waitress, and as such, has no clue what Sheldon and Leonard talk about when they get into a physics conversation. Consequently you do not write lines for Penny that make her smarter than she actually is. A character must speak to her level of understanding.
Go to coffee shops, lunch counters, bars, airports, malls, sporting events; go anywhere there are people from different walks of life. Listen to their rhythms, their sounds, their words. Some people have an ear for music; as a writer you need an ear for the music of words. (Even when there is no dialogue, a writer still needs to know the music of words for the rhythms of the sentence and the flow from one to the other).
People don’t talk like people write, so don’t write dialogue like it is a sentence in a text book. Dialogue can also, and should, reveal character. If a character is pompous, then put on your pompous face and talk with pomposity. No jokes please, I’m trying to be helpful.
Clancy, my flapper character in “Loonies in Hollywood” was a young, spoiled girl, who lived the flapper life. She had a carpe diem personality and her actions, and certainly her dialogue, reflected who she was. It was odd, but when writing her, I often heard her talk, as if she was whispering in my ear. I listened to her. It also helps to be loony. If you’re not loony, then follow my advice. If you are loony like me, you’ve got problems. But you know dialogue.
Cemetery Tales and other Phantasms: http://www.amazon.com/Cemetery-Tales-other-Phantasms-Nelson-ebook/dp/B00G9JND9Q/ref=la_B00EEVHN38_1_2?s=books&ie=UTF8&qid=1390363318&sr=1-2