Foreshadowing as a literary device refers to the author providing the reader with a clue as to what will happen later in the story. This obviously piques the reader's interest and encourage him/her to read further.
In chapter three, three events foreshadow what is to happen at the end of the novel. The first is when Candy's old dog and companion is shot and killed by Carlson. Carlson wanted to get rid of the dog because he believed it was a nuisance and smelled bad. Candy initially refused to have the animal destroyed in this manner. It had been his friend for such a long time and was the only thing he actually really cared about. As a broken and lonely old man, caring for the animal provided him with a sense of purpose and comforted him. Its sudden and brutal demise at the hands of an uncaring Carlson was something he found distasteful.
Unfortunately, Carlson got his way. Candy reluctantly agreed to the dog's execution and Carlson used his gun to kill it. This vile act traumatised Candy and he drew into himself and could not speak for some time.
The second incident is when George speaks about Curley's wife and mentions the following:
"She's gonna make a mess. They's gonna be a bad mess about her. She's a jail bait all set on the trigger. That Curley got his work cut out for him. Ranch with a bunch of guys on it ain't no place for a girl, specially like her."
He furthermore relates an incident in which a ranch hand got into trouble at another ranch where he and Lennie had worked previously. The ranch hand was arrested and found guilty and is serving time in San Quentin.
The third incident is when Lennie breaks Curley's hand after the latter attacked him. Lennie, who has huge hands, enfolds Curley's hand with his and exercises a vice-like grip from which Curley cannot escape. In the process, he breaks all the bones in his hand. The text reads:
Curley's fist was swinging when Lennie reached for it. The next minute Curley was flopping like a fish on a line, and his closed fist was lost in Lennie's big hand. George ran down the room. "Leggo of him, Lennie. Let go." But Lennie watched in terror the flopping little man whom he held. Blood ran down Lennie's face, one of his eyes was cut and closed. George slapped him in the face again and again, and still Lennie held on to the closed fist. Curley was white and shrunken by now, and his struggling had become weak. He stood crying, his fist lost in Lennie's paw.
These three events all foreshadow the death of Curley's wife at Lennie's hand. The incidents illustrate firstly, that just as the dog is a mere object in Carlson's eyes that can be conveniently disposed of, so is it with Curley's wife. She is a mere possession to him. He does not truly love her and the result is that she turns to the ranch hands for attention. It is this which brought her into contact with Lennie and lead to her unfortunate demise. Furthermore, references to Carlson's gun are repeated at the end as well. They would shoot Lennie as if he were a dog.
Secondly, George's reference to her being a danger is precise. Once Lennie had accidentally killed her, he was in exactly the same situation as the ranch hand that George referred to. His prediction about Curley's wife in this instance was accurate.
Thirdly, Lennie's altercation with Curley is an almost precise depiction of his dilemma with Curley's wife, as the following extract illustrates:
He shook her then, and he was angry with her. "Don't you go yellin'," he said, and he shook her; and her body flopped like a fish. And then she was still, for Lennie had broken her neck.
Lennie crushes Curly's hand and the death of Candy's dog are examples of foreshadowing. George remarks that Lennie did not mean to crush his hand, and this alludes to the fact that George has not thought of the implications of Lennie not knowing his own strength.
Candy's dog death is a example of foreshadowing. They killed the dogs since it was old and had no reason to live, just getting in people's way and it was also in a bad condition so best choice was to shoot him.That later alludes to Lennie being shot by George at the end of the book. It was best for everyone including Lennie for him to be killed. He was innocent since his mind didint process what he was doing but at the same time he was harming things and killing things without him even knowing he had done wrong.