This popular hook sentence consists of a powerful, interesting or memorable quote related to your main idea / topic / theme. It is best if the quote comes from a famous person since the reader might find the quote boring if it comes from a person they do not know. 

Example

If you are writing an essay on the corrupted American Dream in The Great Gatsby, then you could use this quote:

“The American Dream may be slipping away. We have overcome such challenges before. To recover the Dream requires knowing where it came from, how it lasted so long and why it matters so much,” states Jon Meacham.

Quotations should encourage the reader of your essay to think more about the main idea / topic / theme of your essay.