Steinbeck referred to this story as a play/novel, and we can see how closely it does resemble a play. Each section or chapter is set in a clearly defined place like a scene in a play.
In addition, the beginning of each section contains detailed description, like stage directions in a play, while the rest of each section is mostly dialogue.
This may seem like a rather artificial way to write a novel, but Steinbeck does it so skillfully that we seldom notice. In fact, this story was adapted as a successful play very shortly after its publication as a novel.
A noticeable feature of the language of the novel is what a critic might call 'economy'. That is, the language is simple, without unnecessary detail.
One result of this is that almost every sentence is important in one way or another, either in developing a character, moving the plot forward or hinting at action still to come.
Steinbeck has skillfully woven a number of parallel events into the story. Candy and his dog provide a parallel to George and Lennie. Similarly, when Lennie kills Curley's wife, it echoes his earlier killing of the puppy.
There are many such echoes and parallels in the book. See what others you can find.
Steinbeck has also showed skill in capturing the spoken language of the characters.
Most of them are uneducated, and this shows through in their use of colloquial and ungrammatical language.
Even their uneducated pronunciation has been shown. Steinbeck worked as a casual farm labourer for a time, so we can expect this to be an accurate reflection of real speech.
Steinbeck also uses colours and sounds to great effect. For example, Curley's wife is associated with red, symbolic of danger or passion perhaps.
A further strong association is that of Lennie with animals.
At various times he is described as a bull, a bear and a dog. Even when not directly compared with an animal, he is described in animal terms. For example, his hand is a paw. This is particularly appropriate for Lennie, as he frequently acts in the simple, natural way of an animal.
As a final note, it is worth pointing out the significance of the name Soledad - the town near where the story is set. In Spanish, it means loneliness - a cue to one of the major themes of the novel.