Hardy's style in Jude the Obscure is somber, intellectual, interrogative and—although there are some sparkling moments of wit—mostly quite serious. This author's writing is characteristically dense, poetic, and lyrical, but in this tragic novel it also becomes intensely philosophical. His realistic, detailed descriptions are intertwined with forceful and frequent reflections on human nature. These happen through the narrator and focus on the nature of marriage, the role of religion in Hardy's contemporary culture, and the limited lives that Victorian society allowed people to lead. Hardy's diction—in service of all of these things—is often academic, with long, involved sentences full of allusions and biblical references.
His syntax also differs significantly between the "voices" of the narrator and the various characters. His characters speak, for the most part, quite plainly and clearly. There are some exceptions to this plainspoken clarity in the high-minded conversations the author recounts between Jude, Sue, and Phillotson, but not many. Hardy's narrator's speech differentiates itself from this plainness through its complexity and its detail. No moment is too small in this book for the narrator to engage with in great detail and at great length, teasing out its political and emotional implications in thorough, figurative language.
The novel is quite slow-paced and repetitive. A great many of the same structures, symbols, and motifs recur, as if to stylistically demonstrate the repetitive and numbing cycles of Wessex life. Hardy's characters often return to situations they've left behind, say things they've previously said, and do things they've done before. This is not represented positively, as to return to anything (a town, a wife, a trade) in this novel is usually to return to it regretfully. Hardy illustrates his characters' limited circles of movement and conveys their sense of frustration and entrapment through these moments of repetition.
