1) Of Mice and Men is a tale of two men, Lennie and George, who travel across a region of California in order to find work during the great depression. When they finally do find work at a ranch things don't go according to plan due to Lennie's mental disabilities which leads he and George to be harrassed. Lennie's actions result in the downfall of he and George's dreams to own their own land.
2) Companionship is a main theme in the novel. Even though it's incredibly obvious that Lennie brings George down George stays with him because he knows that Lennie couldnt survive on his own, and George likes the company. When they arrive at the ranch friendships are formed and brotherhoods grow especially with Crooks and Lennie. Curly's wife even confides in Lennie because she's lonely and wants to find some companionship.
3) The tone of Of Mice and Men is somber, serious, and rough. Capturing the feeling of the era, the Great Depression. At times the novel can even move the reader to tears and make the reader feel great sympathy for the characters
4) Foreshadowing: The title is taken from a poem which states "The best laid schemes o' mice an' men / Gang aft agley." (The best laid schemes of mice and men / Go often askew.) this lays down in concrete the idea that things will not go according to plan.
Symbols: The characters are from Soledad which means "Solitude" in Spanish
Setting: The Great Depression in the California valley is self explanetory, its rough, tough, miserable, dry, and there is no work to be found.
Irony: Lennie has obsessions with small, soft, defensless creatures, which completely contradicts his stature and helps to define his character.
Metaphor: Lennie is innocent and defensless like the rabbits and mice he loves.