Mrs Dalloway is written in the modernist literary style. The novel is narrated using stream of consciousness, which Woolf helped make famous—the style was also popularized by James Joyce's Ulysses, which Woolf herself criticized before eventually writing Mrs Dalloway.
As a result of the narrative's use of stream of consciousness, ideas are often stretched across entire paragraphs or pages, with a number of asides and interruptions that all ultimately feed back into the original consideration. In this way, the narrative style helps Woolf take otherwise simple observations—like, for instance, the sound of a car moving through a crowded street—and turn them into long thought processes that shed light not only on the characters but also the society in which they live.
Furthermore, the narrative often seamlessly transitions from focusing on one character to exploring the perspective of another. Because the novel is so interested in exploring the small details of everyday life, such transitions often make use of some aspect of the surrounding environment. For instance, when the large clock known as Big Ben strikes the hour, the narrative sometimes uses the sound as a way of moving from one's character's experience to another's, narrating the way they perceive the sound as a means of shifting gears without an abrupt break in the narrative thread. As a result, readers get the feeling that all of the characters are more or less experiencing their own versions of the same thing. The loose and flexible style therefore enables Woolf to create a fully realized, complex environment and sense of unity.