I'll begin with foreshadowing, since its purpose is fairly straightforward. In "There Will Come Soft Rains", foreshadowing is evident in the reading of the poem. The poem suggests that "Not one would mind, neither bird nor tree/if mankind perished utterly." The humans are already gone at the beginning of the story, but this hints that the last vestige of humanity, the house, will be destroyed as well. Another example is in the death of the dog. Besides the house, the dog is the only character to which the reader can identify, & the only living thing in this post-apocalyptic setting. When the dog "spun in a frenzy and died", it hints that the house too, may end in a frenzy, and die itself.
This particular story, like many of Bradbury's works, is rich with figurative language. The entire story is centered around the use of personification, as the house is essentially the protagonist. Some examples of personification used include:
"It had shut up its windows and drawn shades in an old-maidenly preoccupation with self-protection which bordered on a mechanical paranoia."
"But the fire was clever."
"The house shuddered, oak bone on bone, its bared skeleton cringing from the heat, its wire, its nerves revealed as if a surgeon had torn the skin off to let the red veins and capillaries quiver in the scalded air."
This last quote is particularly intense, as it combines personification, metaphor, and simile in one vivid package. All of these examples, (and many others) combine to form a perception of the house as life-like and intelligent. This evokes sympathy from the reader, as the house is the only character (except perhaps the dog) to which all can relate. One can feel the isolation and loneliness, and feels sorrow at the passing of the house, almost as though a person is perishing, rather than an inanimate object.