In the short story "The Black Cat" by Edgar Allan Poe, the author uses several literary devices to build suspense throughout the narrative. Some of the techniques Poe uses to build suspense include:
1. Foreshadowing: Poe uses foreshadowing to hint at the impending doom that will befall the narrator. For example, the narrator's description of his first black cat, Pluto, as "a brute which I fear" foreshadows the violence that will occur later in the story.
2. Symbolism: Poe uses symbolism to create a sense of foreboding and unease. The black cat, for example, is a symbol of the narrator's guilt and conscience, and its appearance and behavior throughout the story create a sense of dread and fear.
3. Repetition: Poe uses repetition to create a sense of unease and to emphasize the narrator's descent into madness. The repetition of the phrase "the beating of the hideous heart" throughout the story creates a sense of dread and builds suspense.
4. Ambiguity: Poe uses ambiguity to keep the reader guessing and to create a sense of unease. The unreliable narrator and the mysterious circumstances surrounding the disappearance of the second black cat create a sense of uncertainty and tension.
Overall, Poe's use of these literary devices creates a sense of suspense and unease that builds throughout the story, culminating in a shocking and violent ending.