In his popular novel The Adventures of Huckleberry Finn, Mark Twain uses several dialects. In the introductory text at the beginning of the novel, Twain mentions that he includes a few dialects that were predominantly spoken in the South, especially in Missouri and the regions around the Mississippi River, which is the main setting of the novel. These dialects include the "Missouri negro dialect," "the extremest form of the backwoods Southwestern dialect" and "the ordinary 'Pike County' dialect," as well as "the four modified varieties of this last." Jim's distinctive and quite noticeable dialect is actually this Missouri negro dialect, which was mainly spoken by slaves.
Slaves in nineteenth-century America were regarded as property; they were mainly taught how to take care of the household and how to be obedient servants to their masters and mistresses. Thus, they were prohibited from receiving any formal education.
Jim skips letters and makes the words shorter or even joins them together, so that he can make the pronunciation of those words and phrases easier. His dialect can be described as colloquial and nonstandard, as well as a bit stereotypical. For example, at the end of the novel, Jim says to Huck:
Dah, now, Huck, what I tell you?—what I tell you up dah on Jackson islan’? I tole you I got a hairy breas’, en what’s de sign un it; en I tole you I ben rich wunst, en gwineter to be rich agin; en it’s come true; en heah she is! dah, now! doan’ talk to me—signs is signs, mine I tell you; en I knowed jis’ ’s well ’at I ’uz gwineter be rich agin as I’s a-stannin’ heah dis minute!
Here we can see just how strong Jim's dialect truly is: he speaks rather informally, without any regards to grammar or proper pronunciation. Twain even deliberately makes spelling and grammatical mistakes (a tactic known in literature as eye dialect) whenever he writes Jim's dialogues and monologues, to further accentuate the strength and uniqueness of the Missouri negro dialect.
Twain's use of different dialects in his storytelling is quite important, as it paints an authentic, vivid and historically accurate portrait of the South in the nineteenth century. By incorporating these various dialects in the narrative, Twain defines the identities of his characters and makes the story seem more believable and realistic.