The most fundamental aspect of a quality essay is its grammar. Without fluid and well-punctuated sentences, correctly spelled words, parallel sentence structure and correctly used words, an essay will break down as the reader fails to understand what the writer is attempting to communicate. Some of the most common grammatical mistakes involve punctuation and word choice. Remember to correctly use "they're," "their" and "there." Additionally, keep in mind that "it's" is a contraction of "it is," while "its" is a possessive pronoun. The most effective way to keep one's writing grammatically correct is to learn the fundamentals of grammar from the ground up. Coming to an understanding of the names for the different parts of a sentence will greatly enhance one's ability to use correct words and punctuate sentences well.
Although the success of an essay hinges on its structure, not all essays are structured the same. When students are first taught how to craft an essay, they are often taught to structure the piece with an introduction, three supporting paragraphs and a conclusion. However, many of the greatest essays lack this structure, and often, this kind of architecture can lead to a stale and unexciting essay. The important thing when considering structure is that the essay coherently leads the reader from idea to idea and that the ideas move in a forward, dynamic fashion. Although the first sentence of each paragraph does not necessarily have to make the paragraph's subject explicit, it should clearly reflect the subject. Additionally, it is sometimes helpful to add a sentence at the close of each paragraph that in some way leads into the subject of the succeeding paragraph -- such a "lead-in" is called a segue and assists the reader in following the essay's line of thought.
Even if an essay is grammatical and well-structured, it's going to fail if the content doesn't engage the subject in a thoughtful or critical manner. Derivative of the French word "essayer," which means "to try," an essay does not necessarily require the writer to come to a neat conclusion; rather, an essay should ask critical questions, think further than the superficial and ask the readers to reconsider their presumptions concerning a given topic. One should always examine the essay's thesis with the question, "So what?" Rather than making qualitative statements such as "The Great Gatsby is a great novel," justify why the novel is great by writing something like, "F. Scott Fitzgerald's symbolic imagery in 'The Great Gatsby' serves to highlight the tragic implications of the 'American Dream' in early twentieth-century America." Remember, an essay is not simply an exposition that describes a topic in detail; an essay probes the topic with criticism and details the topic's hidden implications.
Although a grammatical, well-structured and thoughtful essay may be enthralling, it will likely fall flat when the reader comes to the end and finds it written without references. The fact is, essay writing doesn't occur in a vacuum; essays are written amid discourse and collective knowledge. Even geniuses include references with their essays because they know that, despite their innate abilities, their knowledge of the subject is informed by the knowledge of writers before them. Additionally, references are important to an essay's purpose in expanding a reader's knowledge. They provide the readers with further reading, allowing them to find resources through which to expand their own knowledge of the topic. There are a number of ways to note references, the most common being the MLA style, which is asked for by most college instructors.