The list of literary devices used in Steinbeck's The Grapes of Wrath is a long one, but here are just a few examples.
Literary devices are forms of figurative language, also known as figures of speech. They are not to be taken literally: these statements are descriptive in nature, making what is being discussed or described more vivid in the reader's mind.
For example, there is the simile. This literary device compares two dissimilar things as if they were the same. They are, in fact, not the same, but they do share similar characteristics, and "like" or "as" is used. "She's like the wind" compares "she" to "wind." It does not mean that when she is around trees, trashcans and power lines are knocked down, or that she can lift a kite in the air. More likely it means that she is a free spirit and cannot be contained or controlled, anymore than the wind.
In this example from the novel, several devices are used:
The Bank--or the Company—needs—wants—insists—must have—as though the Bank or the Company were a monster, with thought and feeling, which had ensnared them.
First, a simile is used. The "Bank" or "Company" is compared to a monster. The bank is not a living thing, but associated with it is monstrous behaviors. It personified: that is, it is given human characteristics of needing, wanting, insisting, and thinking (and being monstrous—inferring intelligence). (It is also capitalized, as a name would be.) This quote also uses metonymy, where the name given to some thing comes from things associated with it. The bank is not a living thing, but those who run the bank—management, stockholders, etc.—are referred to en total as the "Bank" or the "Company" rather than managers or owners, and it is not the building's behavior that is monstrous, but the actions of those associated with it.
Personification is used again here:
And the little screaming fact that sounds through all history: repression works only to strengthen and knit the repressed.
A fact does not scream, and repression does not work or knit.
The next quote is ironic. The definition of irony varies: it can be the difference between what is said and what is meant, or it can be the difference between what you expect to happen and what really happens.
You're bound to get idears if you go thinkin' about stuff.
It is an ironic statement in that ideas can only come by thinking; it is, however, inferred that one might avoid getting "idears" if one avoids thinking about things.
Hyperbole is the use of exaggeration. In the following, thousan' is used to indicate the wealth of possible life outcomes. While people have choices regarding how they choose to live or work, a thousand is an exaggeration.
Up ahead they's a thousan' lives we might live, but when it comes it'll on'y be one.
There may be dozens of opportunities—choices to define our lives— but here the use of thousan' does not refer to an exact number, but to the vast amount of hope there is for a different life. The opportunities may be wide-ranging, but in the end we can choose only one. This infers that the choice is an important one, for it may be the only one we get.
Finally, personification is used again here:
Death was a friend, and sleep was Death's brother.
Death is not a human being: it is a state of being. Therefore, it cannot have the human characteristics of being a friend—or a brother; neither can sleep be a brother.