Green Light
The green light on Daisy's dock represents Gatsby's hope to reunite with her.
"[Gatsby] stretched out his arms towards the dark water in a curious way... I [Nick] glanced seaward and distinguished nothing except a green light... that might have been the end of a dock. When I looked once more for Gatsby he had vanished, and I was alone again in the unquiet darkness." (pg. 26)
Although we were unaware at the time of Gatsby's infatuation with Daisy and had already been introduced to both characters but had no idea they were connected, this line foreshadows that he is optimistic for being able to be with Daisy. But when Gatsby vanishes from the scene when he looks at the green light, this tells us that Daisy will also vanish from Gatsby's life.
The Reunion
Even the day Gatsby and Daisy reunited foreshadowed trouble.
"The day agreed upon was pouring rain." (pg. 88)
Pathetic fallacy was used here to foreshadow that their relationship would not work.
The Clock
Gatsby's love blinds him from seeing the consequences that will happen in the future. In chapter five, a clcok sits on the mantle at Nick's house where Gatsby and Daisy will reunite. Out of nervousness, Gatsby knocks it over. Fitzgerald was most likely referring to the time lost or the little time left, and foreshadows that he will stumble upon dilemma for trying to relive the past, and will stop at nothing when trying to win Daisy back.
"Can't repeat the past?" he cried incredulously. "Why of course you can!" (pg. 116)
Superficial Love
Even though Gatsby and Daisy seem to get along after the reunion, there were a few parts of the book that foreshadowed their separation, such as Daisy's superficial love for Gatsby.
"They're such beautiful shirts," she sobbed. "It makes me sad because I've never seen such- such beautiful shirts before." (pg. 98)
Daisy only cries when she sees the shirts because she realizes that he has become wealthy which sparks a materialistic love for him. Since this isn't a true form of love, this foreshadows that she never really loves him, just his money.
Tom
Right from the beginning of the novel, it is clear that Tom and Daisy do not have a good relationship going. Tom is not a supportive father and is never there if or when Daisy needs him, he cheated on Daisy with Myrtle, and Daisy only chose Tom because she liked the luxury of the lifestyle and the security he was able to provide. This horrible behavior foreshadowed that Daisy feels she can cheat since Tom did it to her.
The Excuse
One thing that foreshadows Tom's choice to keep Daisy over Myrtle is when Nick finds out Tom's excuse for why he has not divorced Daisy to marry Myrtle. Tom lies about Daisy being Catholic, who don't believe in divorce, so that he can stay with her. The thing is that Tom was a shallow person in a materialistic society. Tom doesn't want to leave Daisy because "her voice is full of money." Tom chooses her "because he is so callous and superficial, he will stay with Daisy just to make himself look better." Another thing to keep in mind is that Tom likes to have power. To do this, he will have to keep Daisy.
Suspicion
Tom seems to have an ego about himself. He is controlling and likes to be superior. Tom treats Daisy as if she is valuable property and becomes suspicious of Gatsby who threatens to take Daisy away from him. Since Tom doesn't trust Gatsby, this foreshadows a conflict between the two, especially if he has a temper and tends to jump to conclusions.
I Can Feel The Heat
After Tom eventually finds out that Gatsby and Daisy are having a secret affair, he gets jealous. Tom knows exactly why Daisy loves Gatsby and wants to keep her away from him so he invites Gatsby over to finish things off. Gatsby is invited over on the hottest day of summer where pathetic fallacy was used to foreshadow the rise in tension.
Myrtle's Death
One of the many details foreshadowing Myrtle's death was the abuse from Tom. In chapter two, Tom hits Myrtle because she refuses to stop saying Daisy's name repeatedly.
"Tom Buchanan broke her nose with his open hand. There were bloody towels upon the bathroom floor and women's voices scolding, and high over the confusion a long broken wail of pain." (pg. 41)
Another, is the amount of reckless driving incidents that occur in the early chapters of the novel. In chapter three, a car accident occurred because of bad driving where Owl Eyes was behind the wheel driving impaired and crashed into a ditch. Something else that foreshadows the death is when Nick states that Jordan is a "rotten driver." In response to what he says, Jordan says that she is allowed to drive badly as long as everyone else around her is driving carefully and that "it takes two to make an accident." This foreshadows that Myrtles death would be due to careless driving. Another event is all of the constant travelling between Long Island and New York. It made it likely some important event would occur there and that it would involve Myrtle since Tom drove back and forth from East Egg to New York all the time to visit her. Also, right before the death, Nick, Tom, and Jordan are all driving home, and they don't realize it yet but they are driving towards the scene of Myrtle's death which takes place in the Valley of Ashes. It is a grey, barren wasteland. When the name and description were introduced at the beginning of the book, it gave me a bad feeling like something lifeless and empty, like death, would occur there. I believe that "ash" was the symbolism used to foreshadow later events.
Gatsby's Death
All major events and characters are involved with foreshadowing Gatsby's death. In chapter two, Owl Eyes was cautious and acted as if Gatsby's house was falling apart. This shows that his house is unstable, which foreshadows that Gatsby's downfall reflects his life (breakable house, breakable life).
Since Nick is so close to Gatsby throughout the entire novel, in chapter eight, when Nick cannot sleep which foretells Gatsby is in trouble.
"I couldn't sleep all night; a fog-horn was groaning incessantly on the Sound, and I tossed half sick between reality and savage frightening dreams. Toward dawn I heard a taxi go up Gatsby's drive and I immediately jumped out of bed and began to dress- I felt that I had something to tell him, something to warn him about and morning would be too late." (pg. 154)
Nick has a nightmare and a feeling that he needs to warn Gatsby of something which foreshadows trouble headed directly towards Gatsby.
The day Wilson arrives to kill Gatsby, Gatsby decided to take a swim in the pool, and the day he swims is the first day of autumn. Autumn,as many people know, is the season where nature starts to die. Even Jordan Baker said that "life starts all over again when it gets crisp in the fall." This foreshadows Gatsby's death because, like the season, life starts to die. Summer, when Gatsby's life and his romance with Daisy were flourishing, signifies liveliness. On the other hand, Autumn, when Gatsby's death occurred and also the death of his relationship with Daisy, signifies death. Just like Jordan said, by things starting over, it foreshadows that everyone will start fresh.
Before swimming in the pool, Gatsby was wearing his famous pink suit. To me, the color pink represents good life and health. However, when he takes off the suit to get in the pool, that good life and health are stripped away leaving him vulnerable. Combined with the pathetic fallacy of Autumn, this foreshadowed his death.
Water is also used in the novel before the death scene. In chapter six, Miss Beadeker complained about drowning in a pool. The two scenes are connected by the use of imagery. Another foreshadow is that it rained during the reunion of Daisy and Gatsby, possibly giving us a hint that there would be more trouble with water in the future.
The Funeral
The funeral scene is proof that society is shallow. Many people knew of Gatsby but few attended his funeral. This materialism was hinted at constantly throughout the book. This foreshadows that Gatsby would have a tragic fall and that he was truly alone, despite that he had everything anybody could ever want.
If Kilpspringer truly cared for Gatsby, he would have played music when asked instead of making a big deal out of it. His grouchy behavior shows irritation towards Gatsby and foreshadows his lack of appearance at Gatsby's funeral. In fact, no one really cared for Gatsby, they just cared about all of the material items and parties. Nick even comes to the conclusion that no one really knows Gatsby despite all of the public appearances and parties.
In fact, many rumors go around about Gatsby which create an image in people's minds that Gatsby is all fun and games instead of the truth which was indeed Gatsby was struggling. This foreshadows that few people would attend the funeral. Nobody feels bad for him or any remorse because they think he has no problems.
In the beginning, when Gatsby is hopeful to be with Daisy but then vanishes when looking at the green light, it foreshadows not only that they will never end up being happily together, but that Daisy would do the same exact thing - abandon him later.
"They were careless people, Tom and Daisy- they smashed up things and creatures and then retreated back into their money or their vast carelessness, or whatever it was that kept them together, and let other people clean up the mess they had made."
In conclusion, Fitzgerald uses foreshadowing many times in The Great Gatsby, and not only does it strengthen the plot, but it brings the novel to life.