What am I supposed to write about on my college essay?
College essays are truly your opportunity to show who YOU are. You get to choose (most of the time) a selection that you would like to write an essay about and have free reign to write a personal story about who you are in relation to this subject. That isn't to say that you should write about something that only YOU think is interesting. You should tailor your answer to something that you think a college would want to know about you in a positive light. For example, if your selected prompt is to write about a time that you overcame an obstacle and what it taught you about yourself, you wouldn't want to write about that time that you got away with tricking your parents into thinking that you were going to work when you were really going to a party. That is the kind of story that you tell your friends, not your prospective college. You'd want to choose something that shows a trait that a college would value in a student coming to their school. A better thing to write about would be the English paper you waited until the last second to write that you failed, and how you worked with your teacher and tutors to correct and re-write your assignment and you realized that true working hard at something was much more valuable to your self esteem than doing the bare minimum. You're not making up a story, you're telling a story that has value for the situation you're writing for.
What is the green light symbolic of in The Great Gatsby and why?
While this is somewhat subjective, the green light is symbolic of the hope that Gatsby feels about his (impossible) future with Daisy. The light is discussed a few times throughout the novel and is quite literally across the bay from Gatsby on Daisy's dock. While it appears to be close enough to be reachable, Gatsby never quite makes it into the entirely different world that Daisy lives in to attain this love that he has dreamed of since their first meeting years before. Essentially, Gatsby builds an entire life to try to reach the unattainable goal of being with Daisy and like the green light, he gets just close enough to think that it is a real possibility, only to be beaten back ceaselessly by the realization that he will never win her over.
How do I know whether to use "there", "their", or "they're"?
If you are talking about a place, you would use "there". Ex: I told Alex that I would meet him over there by the water fountain. If you are talking about something that belongs to someone you would use "their". Ex: Their coffee mug is sitting on the counter. The word "they're" means "they are" so you would use this form of the word when you are using a sentence that you would normally use both words in. Ex: Frank told me that they're going to go to the fair tomorrow.