Edward P. Bailey and Philip A. Powell's The Practical Writer provides an excellent source of writing instruction and tips that the student may wish to consult, for this book will provide a blueprint for the composition of a five-paragraph essay. First of all, here is a definition of an expository essay taken from a Writing Lab of Purdue University:
The expository essay is a genre of essay that requires the student to investigate an idea, evaluate evidence, expound on the idea, and set forth an argument concerning that idea in a clear and concise manner. This can be accomplished through comparison and contrast, definition, example, the analysis of cause and effect, etc.
Therefore, the expository essay is very objective and should be written in third person, of course. If, for instance, the student wishes to write expository essays on a poem, he/she can point to how certain poetic devices serve to develop the theme of the poem, or how the tone, diction, and rhyme of a poem contribute to the theme and meaning of a poem. Thus, the essay becomes a literary analysis. This analysis, then, follows a distinct pattern:
1. Motivator - This is the first sentence which strives to gain the reader's attention. It can be a quotation, a personal inflection--sometimes, even a question. This sentence relates to the thesis.
2. Thesis Statement - This is a general statement that the author can support, and it carries the main idea of an essay. For example, if discussion of a poem is the topic, the writer can state that the use of figurative language and a certain style of diction direct the reader to the theme of the poem.
In the body of the essay, the student develops the thesis which has 3 opinions. Each opinion about the general statement becomes the topic sentence of the paragraph. This topic sentence is, then, developed through the use of supporting details such as examples from the poem that the student is analyzing. It is very important to support any points that are made since doing so lends credibility to the essay. (State a point and then provide an example from the poem--"evidential support"). Using transitions between ideas and sentences creates coherence since transitional words act as links to the chain of thought in an essay. Lead into the first line of the next topic with the last sentence of a previous paragraph that is reworded.
A sense of finality is created by the last paragraph if it contains a reworded thesis statement and what is called "a clincher." The conclusion summarizes the "evidence" provided in the analysis. A clincher is the finishing touch; it is the final sentence that erases all doubt in the reader's mind that the essay has ended.
With the example of the essay as an analysis of a poem, the writer will, then, summarize the main points made and tie them together with the "clincher," a sentence that leaves no doubt that the essay is at an end and reminds the reader of the motivator. Often this sentence begins with such words as "clearly," "certainly," "finally," "indeed," etc.