This is a really big question. I'm not sure I can answer all of it in one shot. We're dealing with five major literary devices, each of which requires a decent amount of explaining.
Foreshadowing, a technique used by authors to indicate to the reader events that might occur later in a story, occurs at very first in the beginning of "The Monkey's Paw" when Mrs. White describes the setting; the place in which the White family resides. "'Of all the beastly, slushy, out-of-the-way places to live in, this is the worst. Pathway's a bog, and the road's a torrent. I don't know what people are thinking about. I suppose because only two houses in the road are let, they think it doesn't matter.'" This foreshadows negative events or scary events. She describes a gloomy setting, perfect for a horror story. In addition, they live in a hard-to-get-to place, meaning that if something bad were to happen, help might not be able to reach them. Over all, her description of the environment gives the reader a feeling of spookiness and discomfort.
In addition, bad events are foreshadowed when the general talks about how he came into possession of the paw. "'The first man had his three wishes. Yes,' was the reply; 'I don't know what the first two were, but the third was for death. That's how I got the paw.'" This foreshadows something bad is going to happen if anyone tries to wish on the paw, and it is clear at this point in the story that Mr. White intends to wish on the paw.