Expository writing requires the writer to investigate an idea, expound on the idea, evaluate evidence and then create a clear and concise argument around that idea. Expository essays can be in the form of a comparison and contrast, analysis of cause and effect, or an explanation or analysis of a definition or process. Depending upon the purpose, each paragraph should be written to reflect that purpose and communicate your argument clearly to the reader.
Before you can write an expository paragraph, it's a good idea to first understand the structure of an expository essay. Like most other essays, expository essays require a clearly stated and defined thesis statement in the first paragraph of the essay. Writers also need to use logical transitions between all paragraphs, especially between the introduction and conclusion paragraphs. Body paragraphs should include evidential support that can be factual, statistical, logical or anecdotal. Finally, writers should close with a strong conclusion that does not simply restate the thesis statement.
Informing or Explaining
Essays that require you to inform the reader of something, or maybe explain a process, requires that you present the topic in the introduction and then arrange your body paragraphs logically, and usually chronologically, when explaining a process. One method of writing paragraphs for papers that explain or inform readers of something is to use your topic sentences like steps in the process, or pieces of information in the explanation. Topic sentences act as mini-thesis statements for body paragraphs already, but when writing a paper explaining a process, the topic sentences can also act as a guide for your reader through the steps of the process and your argument.
Analyzing or Evaluating
One specific type of explanatory writing is an analysis that is an examination of how and why an issue is significant. Some expository essays require more analysis than explanation, so understanding your aim as a writer will help you to generate effective body paragraphs that communicate your argument to the reader. If you're writing a comparison essay, you should either devote individual paragraphs to each item being compared, or intermix those items or concepts being compared throughout the body paragraphs. If you are writing a cause-and-effect analysis essay, you should begin in the introduction by identifying the cause and effect you are going to analyze. If you are writing about a problem and solution, you should also identify the problem early enough so your proposed solutions make sense. The solution should also be presented in your thesis statement.
Topic Sentences Guide the Way
The purpose of the topic sentence is to tell the reader what that paragraph is going to be about. Each of the supporting body paragraphs should contain topic sentences that cover separate points to develop the argument of the paper. No matter if you are writing a comparison essay or a cause-and-effect analysis essay, the topic sentences should lead your reader from your thesis statement to each subsequent paragraph of the essay. Every paragraph should have a one-sentence statement of the main idea that begins the body paragraphs.