Chapter 3: Paragraph Structure

3.3 Expository Paragraphs

Learning Objectives

  • Provide evidence that supports a thesis, including relevant information on varying perspectives.
  • Articulate concepts and information correctly and concisely.
  • Decide the significance and merit of different facts, concepts and data.
  • Organize an expository paragraph.

The main aim of an expository paragraph is to provide an effective explanation of a topic. While a descriptive paragraph strives to describe a subject and a narrative paragraph seeks to show personal growth, an expository paragraph tries to explain a topic or situation. Thus, expository paragraphs are written as if the writer is explaining or clarifying a topic to the reader. Since an expository paragraph is trying to clarify a topic, it is important that its sentences provide the categories or reasons that support the clarification of the topic. Moreover, these categories and reasons also provide the framework for the organization of the paragraph.

Image described in surrounding text.
Figure 3.1 Components of the expository paragraph as the parts of a house.

Much like the categories are essential to clarifying the topic, organization is the key to any well-developed paragraph. When composing your paragraph, think of its organization as a house, with each major part of a house representing a component of a paragraph. Just as the foundation provides support on which a house can be built, a thesis represents the foundation upon which to build a paragraph. The introductory sentence then functions as both the door and the framework for an expository paragraph. Like a house door, the introductory sentence must allow the reader to enter the paragraph. Additionally, just as walls are built upon the framework of a house, the body sentences of a paragraph are organized around the framework or the organizational scheme that is presented in the introductory sentence. The body sentences, much like the walls of a house, must be firm, strong and complete. Finally, a paragraph must include a concluding sentence that tops off the paragraph, much like a roof completes a house. As the roof cements the structure of the house and helps hold the walls in place, the concluding sentence must sum up the point of your body sentences and complete the paragraph.

Although the overall organization of an expository paragraph is important, you must also understand the organization of each component (the introductory, body, and concluding sentences) of your paragraph. The sections below identify the essential parts of each component of your paragraph, explaining the necessary information for each type of sentence.

While the guidelines listed below may feel constrictive, they are merely meant to guide you as a writer. Ultimately, the guidelines should help you write more effectively. The more familiar you become with how to organize a paragraph, the more energy you can focus on your ideas and your writing. As a result, your writing will improve as your ability to organize your ideas improves. Plus, focusing your energy on your argument and ideas rather than the organization makes your job as a writer more exciting and fun.

Introductory Sentences

A strong introductory sentence is crucial to the development of an effective expository paragraph. Unlike a persuasive paragraph, which takes a stand or forms an opinion about a subject, an expository paragraph is used when the writer wishes to explain or clarify a topic to the reader. In order to properly explain a topic, an expository paragraph breaks it into parts, explains each component in relation to the whole, and uses each component to justify the explanation of the topic. Thus, when writing an introductory sentence, it is crucial to include the explanation or clarification of the topic and the categories or components used to produce this explanation.

Introductory sentences

  • Introduce the issue.
  • Present the topic and its explanation or clarification.
  • Provide the categories used to explain the topic.
  • Provide the thesis statement.

Since the success of the paragraph rests on the introductory sentence, it is important to understand its essential components. Usually, when expository paragraphs fail to provide a clear explanation, it is not because the writer lacks explanations or clarifications, but rather because the explanations are not properly organized and identified in the introductory sentence. One of the most important jobs of an introductory sentence is that it introduces the topic or issue. Most explanations cannot be clarified without at least some background information. Thus, it is essential to provide a foundation for your topic before you begin explaining. For instance, if you wanted to explain what happened at the first Olympic Games, your introductory sentence would first need to briefly mention how the first games happened. In doing so, you ensure that your audience is as informed about your topic as you are, and thus, you make it easier for your audience to understand your explanation.

Below, the main jobs of the introductory sentence are described and explained in detail.

The purposes of introductory sentences

Introductory sentences introduce the topic and suggest why it is important.

Example: An analysis of the essay exam results of the new English class shows that the new class format promotes close reading and better essay organization.

This sentence tells the reader both that the topic of the paper will be the benefits of the new English class and that the significance of these benefits is the improvement of close reading and essay organization.

Introductory sentences outline the structure of the paragraph and highlight the main ideas.

Example: Considering the results of the high school exit exam, it is apparent that the school curriculum is not properly addressing basic math skills, such as fractions, percentages and long division.

This sentence indicates the main ideas (fractions, percentages and long division) of the paragraph and indicates the order in which they will be presented in the body sentences.

Introductory sentences state the thesis.

Example: University and college work experience programs will require all students to take a résumé and cover letter writing workshop in order to better prepare them for employment.

This thesis statement indicates the explanation of the paragraph.

In addition to introducing the topic of your paragraph, your introductory sentence also needs to introduce each of the points you will cover in your body sentences. By providing your audience with an idea of the points you will make in your paragraph, your introductory sentence serves as a guide map, not only for your audience, but also for you. Including your main points in your introductory sentence not only allows your audience to understand where your paragraph is headed, but also helps you as a writer remember how you want to organize your paragraph. This is especially helpful if you are not writing your paragraph in one sitting, as it allows you to leave and return to your paragraph without forgetting all of the important points you wanted to make.

Table 3.7 Dos and don’ts of introductions
Things to always do Things to never do
  • Capture the interest of your reader.
  • Introduce the issue to the reader.
  • State the problem simply.
  • Write in an intelligible, concise manner.
  • Refute any counterpoints.
  • State the thesis, preferably in one arguable statement.
  • Provide each of the arguments that will be presented in each of the body sentences.
  • Apologize: Do not suggest that you are unfamiliar with the topic. (Example: I cannot be certain, but …)
  • Use sweeping generalizations. (Example: All men like football …)
  • Use a dictionary definition. (Example: According to the dictionary, a humble person is …)
  • Announce your intentions: Do not directly state what you will be writing about. (Example: In this paper, I will …)

Most importantly, when writing an introductory sentence, it is essential to remember that you must capture the interest of your reader. Thus, it is your job as the writer to make the introduction entertaining or intriguing. In order to do so, consider using a quotation, a surprising or interesting fact, an anecdote, or a humorous story. While the quotation, story, or fact you include must be relevant to your paragraph, placing one of these at the beginning of your introduction helps you not only capture the attention of the reader, but also introduce your topic and argument, making your introduction interesting to your audience and useful for your argument and paragraph.

Body Sentences

In an expository paragraph, the body sentences are where the writer has the opportunity to explain or clarify their viewpoint. By the concluding sentence, the writer should adequately clarify the topic for the reader. Regardless of a strong thesis statement that properly indicates the major subtopics of the paragraph, paragraphs with weak body sentences fail to properly explain the topic and indicate why it is important. Body sentences of an expository paragraph are weak when no examples are used to help illuminate the topic being discussed or when they are poorly organized. Occasionally, body sentences are also weak because the quotes used complicate rather than simplify the explanation. Thus, it is essential to use appropriate support and to adequately explain your support within your body sentences.

In order to create a body sentence that is properly supported and explained, it is important to understand the components that make up a strong body sentence. The bullet points below indicate the essential components of a well-written, well-argued body sentence.

Body sentences

  • Begin by reflecting the argument of the thesis statement.
  • Support the argument with useful and informative quotes from sources such as books, journal articles, expert opinions, etc.
  • Briefly explain each quote and indicate its significance.
  • Ensure that the information provided is relevant to the thesis statement.
  • Transition into the next body sentence.

Just as your introduction must introduce the topic of your paragraph, the first body sentence must introduce the main subpoint for that sentence. For instance, if you were writing a body sentence for a paragraph explaining the factors that led to Canadian conscription in World War II, one body sentence could discuss the impact of Canada’s relationship with Britain on the decision to conscript Canadian men. To do so, you would begin by explaining why Canada felt obliged to come to Britain’s aid. Your audience now knows what the paragraph is explaining, and you can also keep track of your ideas.

Following the topic sentence, you must provide some sort of fact that supports your claim. In the example of the World War II paragraph, maybe you would provide a quote from a historian. After your quote or fact, you must always explain what the quote or fact is saying, stressing what you believe is most important about your fact. It is important to remember that your audience may read a quote and decide it is indicating something entirely different than what you think it is explaining. Or, maybe some of your readers think another aspect of your quote is important. If you do not explain the quote and indicate what portion of it is relevant to your clarification, then your reader may become confused or may be unconvinced by your explanation. Consider the possible interpretations for the statement below.

Example: While Canada’s involvement in World War II did not lead to as many young men dying as in Britain, a generation was still deeply affected.

Interestingly, this statement seems to be saying two things at once: that Canada’s young men were not killed in the same numbers as those of other Allied countries, and that the number of deaths nonetheless marked a generation. On the one hand, the historian seems to say that the two outcomes are not directly linked. On the other hand, the historian also indicates that the two outcomes are linked in that the deaths caused Canada to be impacted by the war. Because of the tension in this quotation, if you used it for your World War II paragraph, you would need to explain that the significant portion of the quote is the assertion that links the outcomes.

In addition to explaining what this quote is saying, you would also need to indicate why this is important to your explanation. When trying to indicate the significance of a fact, it is essential to try to answer the “so what.” Imagine you have just finished explaining your quote to someone and they have asked you “so what?” The person does not understand why you have explained this quote, not because you have not explained the quote well, but because you have not told them why they need to know what the quote means. This—the answer to the “so what”—is the significance of your paragraph and is essentially your clarification within the body sentences.

Concluding Sentences

The concluding sentence of an expository paragraph is an author’s last chance to create a good impression. Hence, it is important to restate the thesis statement at the beginning of the sentence in order to remind the reader of your topic and explanation. Since it is at the end of the paragraph, the concluding sentence also should add a sense of closure and finality to the clarification of the paragraph. It is important to re-emphasize the main idea without being repetitive or introducing an entirely new idea or subtopic. While your concluding sentence can suggest further research or investigation, do not make this question the focus of the sentence. Thus, you should briefly and concisely reiterate the strongest clarifications of the paragraph, reminding the reader of the validity of your thesis or explanation and bringing closure to your paragraph.


The following is an example of a paragraph that describes why graduating from college is harder than graduating from high school. The paragraph has been broken up to describe the purpose of each sentence (or group of sentences).

Table 3.8 An example paragraph
Purpose Example
Topic sentence There are several reasons why graduating from college is harder than graduating from high school; however, the most important reason is the lack of support.
Introduce and explain one major point that supports your topic sentence. Be sure to provide adequate information to both explain the point and connect the point to your topic. While in high school, the school and the teachers monitor and enforce a student’s attendance, yet in college, a student’s attendance is not monitored and they can decide whether or not to attend class. As a result, many students may choose to go to the beach or to the mall rather than school.
Introduce and explain the second major point that supports your topic sentence. Be sure to provide adequate information to both explain the point and connect the point to your topic. Though a college student’s grades may suffer from missing a scheduled class meeting, high school students are given detention or other forms of punishment. To many college students, this lack of consequences seems freeing, yet it actually reflects a lack of support. Without the college or professors supporting a student’s attendance, the student must make these decisions on their own.
Introduce and explain the third major point that supports your topic sentence. Be sure to provide adequate information to both explain the point and connect the point to your topic. This situation can also be exacerbated by a lack of nearby family and friends. A large number of college students move away from home to attend college, whereas most high school students still live with their parents. Due to this, college students may not have the same support system as high school students.
A body paragraph can contain as many points as needed to explain and support the topic sentence. What is more, some college students may be the only individual from their high school to attend a university. Thus, in addition to leaving their family, a student may find themself friendless.
Concluding/transition sentence Despite the hazardous effects that this lack of support may produce, there are also several other factors that affect a college student’s ability to succeed

Concluding sentences

  • Begin by reflecting the argument of the thesis statement.
  • Briefly summarize the main points of the paragraph.
  • Provide a strong and effective close for the paragraph.
Table 3.9 Dos and don’ts of conclusions
Things to always do Things to never do
  • Stress the importance of the thesis.
  • Include a brief summary of the main idea.
  • Be concise.
  • Provide a sense of closure.
  • Rework your introduction or thesis statement.
  • Use overused phrases. (Example: In summary … or In conclusion …)
  • Announce what you have written in the body of the paragraph. (Example: In this paragraph, I have emphasized the importance of …)
  • Apologize. (Example: Although I do not have all the answers …)
  • Make absolute claims. (Example: This proves that the government should …)

You may feel that the concluding sentence is redundant or unnecessary. However, do not forget that this is your last chance to explain the significance of your argument to your audience. Just as your body sentences strive to present the significance of each fact or quote you use, your concluding sentence should sum up the significance of your argument. Thus, you should consider making a bold statement in your concluding sentence by evoking a vivid image, suggesting results or consequences related to your argument, or ending with a warning. Through using these strategies, you not only make your concluding sentence more exciting, but you also make your paragraph and your argument more important.

Review Questions

  1. What are three of the main purposes of an introductory sentence?
  2. What should you never do in an introductory sentence?
  3. How should you refute counterpoints?
  4. What is the formula for a well-argued body sentence?
  5. What should you include in a concluding sentence? What should you never include in a concluding sentence?

Points to Consider

  1. Write an expository paragraph about your favourite movie or book, paying special attention to why a certain book or movie is your favourite. Be sure to briefly but adequately summarize the movie or book in order to provide a concise and comprehensible explanation. Additionally, be sure to use concrete details and examples to explain why you enjoy the book or movie you are writing about. Simply summarizing the plot will not explain to the reader why the book or movie is entertaining to you.
  2. Write an expository paragraph about a historical event, indicating at least three factors that contributed to its development. For instance, you could discuss how factors such as residential schools led to the reconciliation movement. A factor could be an event, an individual, or a movement that is historically significant. In order to properly show how certain factors caused or contributed to a specific event, you must clarify both the factors and the event itself.


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Building Blocks of Academic Writing Copyright © 2020 by Carellin Brooks is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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