Chandler is most known for his contributions to the development of what is usually referred to as a "hardboiled" writing style. Marlowe never minces his words or beats around the bush. He is blunt, terse, direct, sometimes dismissive and frequently rude. He talks tough and he talks smart. Throughout The Big Sleep, talking tough becomes a way of asserting power. So what are some of the characteristics of tough talk? Allow Shmoop to elaborate:
Marlowe's a wise guy, or at least he wants people to see him as a wise guy.
A wise guy is someone who talks too much, asks too many questions, and talks back when he should keep quiet. A wise guy goes against authority figures and is contemptuous of the rich and powerful. A wisecrack is any "wise" (i.e. smart-alecky) remark from a "wise guy." In Marlowe's case, his wisecracks also tend to be extremely witty and clever. And Marlowe uses his wit as a kind of weapon to expose people for what they really are.
For example, when Marlowe confronts Brody about the nude photos of Carmen, Marlowe tries to see if Brody had any involvement in Geiger's death by saying, "You shot Geiger to get it. Last night in the rain. It was dandy shooting weather" (14.69). In that third sentence, Marlowe's playing the part of the smart-aleck to test Brody's reactions and control the situation. Chandler drops in these witty wisecracks throughout the novel to make the writing more vivid and lively. And on a thematic level, these wisecracks also show how Marlowe acts as the voice of reason by pointing out people's follies.
In addition to Chandler's famous wisecracks, another stylistic device that's unique to Chandler's style is the simile. Chandler's similes are usually exaggerated or overstated (often for comedic effect) and this quality is a defining aspect of Marlowe's voice as a narrator. Let's take a look at some of the wittiest and most unusual similes in The Big Sleep:
(1) The heat […] made me feel like a New England boiled dinner. (2.46)
(2) Her eyes became narrow and almost black and as shallow as enamel on a cafeteria tray. (12.56)
(3) She was as limp as a fresh-killed rabbit. (14.72)
(4) The boy stood glaring at him with sharp black eyes in a face as hard and white as cold mutton fat. (18.10)
(5) You leak information like a radio announcer. (23.29)
(6) Her eyelids were flickering rapidly, like moth wings. (25. 125)
(7) I was as empty of life as a scarecrow's pockets. (25.1)
(8) There was a dry click, like a small icicle breaking. I hung there motionless, like a lazy fish. (26.9)
(9) The purring voice was now as false as an usherette's eyelashes and as slippery as a watermelon seed. (30.44)
Notice how most of the similes here are negative. They help to emphasize just how jaded Marlowe is, sure, but they also show a sharp and clever mind at work, and Marlowe never runs out of biting remarks to say. Pay attention to how, in each of these examples, Chandler uses the simile to make really unexpected comparisons. What if Chandler had simply written "as limp as a wet noodle"? Sure, that's a pretty good image, but it's also very common. We've all heard that comparison being made many times before. But the simile "as limp as a fresh-killed rabbit" is a much more startling comparison.
Plus there's the vividness and its precision. Take the simile "as false as an usherette's eyelashes." Why is this such an effective comparison? Why not say "as false as a $3 bill"? Because for Chandler, that would be too obvious. Too boring and predictable. Instead, Chandler chooses the more unusual image of an usherette's eyelashes, which has greater comedic effect. Chandler's dedication to perfecting his writing style is what ultimately separates The Big Sleep from the mass of cheap pulp stories and elevates it to the status of high literary art.