The style of Wuthering Heights varies between sweeping, mood-setting description to a dextrous use of dialect that gives insight into characters' beliefs and moral states. In particular, Brontë uses sentence structure and diction of varying complexity, as well as class-coded dialect (fancier and educated vs. heavily accented and implicitly uneducated) to establish tone and advance the narrative.
Educated characters who are associated with civilization, like the Lintons, Catherine, and especially Lockwood, tend to use long, complex, sometimes irony-laced sentences. While Lockwood can be an outlier with his paragraph-long, meandering observations, this verbal complexity provides a sort of baseline for the novel's style.
At the other end of the spectrum are characters whose diction suggests a degree of moral compromise, or at least a reduced position in life. Joseph's long-winded rants, spoken in an impenetrable Yorkshire accent, come to signify his irrelevance and hypocrisy, while gruff, profanity-laden speech from Hindley and Hareton shows that even well-born characters can slip into moral degeneracy (though Hareton's eventual literacy shows they're not fated to remain there).
Nelly Dean, as a modestly educated servant, is somewhere in between, mostly sticking close to the book's standard diction but occasionally switching registers when speaking with other servants or her charges—using regional "thee" or "thy" pronouns, for example. This verbal flexibility fits with Nelly's variable perspective as a narrator.
Almost all characters, especially Nelly and Lockwood, give closely observed descriptions of the natural landscape, which helps convey the pervasive, often dark, sometimes beautiful wildness of the Yorkshire moors; Catherine, in particular, often describes her passionate emotions and affections using such nature imagery, which adds to the novel's heavily atmospheric mood. Brontë also deftly uses dramatic irony to build suspense throughout the novel, giving readers advance insights that characters must later discover through suffering.
