An expository essay requires you to build an argument based on facts instead of your own opinion. Of course, you can start with your own ideas, but you need to have sound research to back them up. Your instructor may give you a topic or she may give you the opportunity to choose your own. Whatever you write about, you should know the basic elements that make up an expository essay.
The structure of this type of essay follows the standard essay format. You will have an introduction, a body and a conclusion. The instructor will tell you the length of your essay assignment, but, in general, expository essays follow a five paragraph rule. The first paragraph gives your introduction, the second, third and fourth paragraphs contain the body of the essay and the conclusion occurs in the fifth paragraph. If your instructor assigns a longer assignment, you may need to include more arguments in the body of your essay.
Your essay will revolve around a single idea, known as your thesis statement. In an expository essay, you need to build a thesis that does not rely solely on your own opinion, but instead, allows you to use research to prove that idea. This idea will go in the introduction of your essay, and the rest of your essay will relate back to this single statement.
The body of your essay will give you the chance to provide the reader with research that proves your thesis statement. If using a five paragraph structure, you will make three points relating back to the main idea. Again, you will rely on research on not your own opinions on the topic to prove the thesis. For example, if your thesis states that a healthy diet contains fruits and vegetables, you may have arguments such as the need for the nutrients in these foods and their possible role in disease prevention. Make sure your arguments aim to prove your thesis statement and that you do not veer off topic.
When you write an expository essay, you need to make sure you write with clarity. This means you need to make sure you relate the research and other information in your essay in a way that readers will understand and follow your ideas. A typical reader will not always notice that you have a clear way of writing, but he will notice when you lack clarity in your essay.
To help you achieve clarity, look at the structure of your essay. Does every argument help prove your thesis? As well, when you share your research, can the reader understand the material and see how it applies to your argument? Does your conclusion help tie your arguments together to prove your thesis statement? Questions such as these will help you evaluate clarity. You may need to have a friend or classmate read through your essay to give you a better insight.