Wide Sargasso Sea is riddled with Caribbean rhythms and speech patterns in the dialogue, as well as the French-patois phrases that show up. The first thing Christophine says is. "she pretty like pretty self" when discussing Antoinette's mother. This helps reinforce the Jamaican setting of the novel. Later, Antoinette says of Christophine, "she could speak good English if she wanted to, as well as French and patois, but she took care to talk as they talked." This seems to indicate that Christophine does not want to stand out from the crowd because of her Martinique heritage. She talks in the same dialect as the Jamaicans to try to avoid some of the rivalry between the English and French colonies.
The most vivid use of dialect, however, appears when we see the story through Rochester's eyes. The French-patois phrases uttered by Christophine appear much more frequently. This could be because of Rochester's insecurities, and his feeling of not fitting in. With Rhys having put them in, the reader, as well as Rochester, can only guess as to the meaning of the words. During this section, Rochester notices that Antoinette can speak patois, and does many times with Christophine. This relates to the strong connection between the two women, and adds to Rochester's alienation.
The last use of dialect relates to the practice of obeah in the novel. Christophine's dialect is filled with it, especially when she says not to mess with it and béké. This, as well as the lack of understanding of obeah among the readers (to which I subscribe), adds to the mystery of the novel.
In Wide Sargasso Sea, Jean Rhys uses dialect to highlight connection between characters, alienation, and the mystery of the landscape in the novel.
