Paragraphs & Topic Sentences
A paragraph is a series of sentences that are organized and coherent, and are all related to a single topic. Almost every piece of writing you do that is longer than a few sentences should be organized into paragraphs. This is because paragraphs show a reader where the subdivisions of an essay begin and end, and thus help the reader see the organization of the essay and grasp its main points.
Paragraphs can contain many different kinds of information. A paragraph could contain a series of brief examples or a single long illustration of a general point. It might describe a place, character, or process; narrate a series of events; compare or contrast two or more things; classify items into categories; or describe causes and effects. Regardless of the kind of information they contain, all paragraphs share certain characteristics. One of the most important of these is a topic sentence.
A well-organized paragraph supports or develops a single controlling idea, which is expressed in a sentence called the topic sentence. A topic sentence has several important functions: it substantiates or supports an essay’s thesis statement; it unifies the content of a paragraph and directs the order of the sentences; and it advises the reader of the subject to be discussed and how the paragraph will discuss it. Readers generally look to the first few sentences in a paragraph to determine the subject and perspective of the paragraph. That’s why it’s often best to put the topic sentence at the very beginning of the paragraph. In some cases, however, it’s more effective to place another sentence before the topic sentence—for example, a sentence linking the current paragraph to the previous one, or one providing background information.
Although most paragraphs should have a topic sentence, there are a few situations when a paragraph might not need a topic sentence. For example, you might be able to omit a topic sentence in a paragraph that narrates a series of events, if a paragraph continues developing an idea that you introduced (with a topic sentence) in the previous paragraph, or if all the sentences and details in a paragraph clearly refer—perhaps indirectly—to a main point. The vast majority of your paragraphs, however, should have a topic sentence.
Most paragraphs in an essay have a three-part structure—introduction, body, and conclusion. You can see this structure in paragraphs whether they are narrating, describing, comparing, contrasting, or analyzing information. Each part of the paragraph plays an important role in communicating your meaning to your reader.
Introduction: the first section of a paragraph; should include the topic sentence and any other sentences at the beginning of the paragraph that give background information or provide a transition.
Body: follows the introduction; discusses the controlling idea, using facts, arguments, analysis, examples, and other information.
Conclusion: the final section; summarizes the connections between the information discussed in the body of the paragraph and the paragraph’s controlling idea.
The following paragraph illustrates this pattern of organization. In this paragraph the topic sentence and concluding sentence (CAPITALIZED) both help the reader keep the paragraph’s main point in mind.
SCIENTISTS HAVE LEARNED TO SUPPLEMENT THE SENSE OF SIGHT IN NUMEROUS WAYS. In front of the tiny pupil of the eye they put, on Mount Palomar, a great monocle 200 inches in diameter, and with it see 2000 times farther into the depths of space. Or they look through a small pair of lenses arranged as a microscope into a drop of water or blood, and magnify by as much as 2000 diameters the living creatures there, many of which are among man’s most dangerous enemies. Or, if we want to see distant happenings on earth, they use some of the previously wasted electromagnetic waves to carry television images which they re-create as light by whipping tiny crystals on a screen with electrons in a vacuum. Or they can bring happenings of long ago and far away as colored motion pictures, by arranging silver atoms and color-absorbing molecules to force light waves into the patterns of original reality. Or if we want to see into the center of a steel casting or the chest of an injured child, they send the information on a beam of penetrating short-wave X rays, and then convert it back into images we can see on a screen or photograph. THUS ALMOST EVERY TYPE OF ELECTROMAGNETIC RADIATION YET DISCOVERED HAS BEEN USED TO EXTEND OUR SENSE OF SIGHT IN SOME WAY.
George Harrison, “Faith and the Scientist”
In a coherent paragraph, each sentence relates clearly to the topic sentence or controlling idea, but there is more to coherence than this. If a paragraph is coherent, each sentence flows smoothly into the next without obvious shifts or jumps. A coherent paragraph also highlights the ties between old information and new information to make the structure of ideas or arguments clear to the reader.
Along with the smooth flow of sentences, a paragraph’s coherence may also be related to its length. If you have written a very long paragraph, one that fills a double-spaced typed page, for example, you should check it carefully to see if it should start a new paragraph where the original paragraph wanders from its controlling idea. On the other hand, if a paragraph is very short (only one or two sentences, perhaps), you may need to develop its controlling idea more thoroughly, or combine it with another paragraph.
A number of other techniques that you can use to establish coherence in paragraphs are described below.
Repeat key words or phrases. Particularly in paragraphs in which you define or identify an important idea or theory, be consistent in how you refer to it. This consistency and repetition will bind the paragraph together and help your reader understand your definition or description.
Create parallel structures. Parallel structures are created by constructing two or more phrases or sentences that have the same grammatical structure and use the same parts of speech. By creating parallel structures you make your sentences clearer and easier to read. In addition, repeating a pattern in a series of consecutive sentences helps your reader see the connections between ideas. In the paragraph above about scientists and the sense of sight, several sentences in the body of the paragraph have been constructed in a parallel way. The parallel structures (which have been emphasized) help the reader see that the paragraph is organized as a set of examples of a general statement.
Be consistent in point of view, verb tense, and number. Consistency in point of view, verb tense, and number is a subtle but important aspect of coherence. If you shift from the more personal "you" to the impersonal “one,” from past to present tense, or from “a man” to “they,” for example, you make your paragraph less coherent. Such inconsistencies can also confuse your reader and make your argument more difficult to follow.
Use transition words or phrases between sentences and between paragraphs. Transitional expressions emphasize the relationships between ideas, so they help readers follow your train of thought or see connections that they might otherwise miss or misunderstand. The following paragraph shows how carefully chosen transitions (CAPITALIZED) lead the reader smoothly from the introduction to the conclusion of the paragraph.
I don’t wish to deny that the flattened, minuscule head of the large-bodied "stegosaurus" houses little brain from our subjective, top-heavy perspective, BUT I do wish to assert that we should not expect more of the beast. FIRST OF ALL, large animals have relatively smaller brains than related, small animals. The correlation of brain size with body size among kindred animals (all reptiles, all mammals, FOR EXAMPLE) is remarkably regular. AS we move from small to large animals, from mice to elephants or small lizards to Komodo dragons, brain size increases, BUT not so fast as body size. IN OTHER WORDS, bodies grow faster than brains, AND large animals have low ratios of brain weight to body weight. IN FACT, brains grow only about two-thirds as fast as bodies. SINCE we have no reason to believe that large animals are consistently stupider than their smaller relatives, we must conclude that large animals require relatively less brain to do as well as smaller animals. IF we do not recognize this relationship, we are likely to underestimate the mental power of very large animals, dinosaurs in particular.
Stephen Jay Gould, “Were Dinosaurs Dumb?”
SOME USEFUL TRANSITIONS
(modified from Diana Hacker, A Writer’s Reference)
- To show addition:
- again, and, also, besides, equally important, first (second, etc.), further, furthermore, in addition, in the first place, moreover, next, too
- To give examples:
- for example, for instance, in fact, specifically, that is, to illustrate
- To compare:
- also, in the same manner, likewise, similarly
- To contrast:
- although, and yet, at the same time, but, despite, even though, however, in contrast, in spite of, nevertheless, on the contrary, on the other hand, still, though, yet
- To summarize or conclude:
- all in all, in conclusion, in other words, in short, in summary, on the whole, that is, therefore, to sum up
- To show time:
- after, afterward, as, as long as, as soon as, at last, before, during, earlier, finally, formerly, immediately, later, meanwhile, next, since, shortly, subsequently, then, thereafter, until, when, while
- To show place or direction:
- above, below, beyond, close, elsewhere, farther on, here, nearby, opposite, to the left (north, etc.)
- To indicate logical relationship:
- accordingly, as a result, because, consequently, for this reason, hence, if, otherwise, since, so, then, therefore, thus
Produced by Writing Tutorial Services, Indiana University, Bloomington, IN
Writing an academic essay means fashioning a coherent set of ideas into an argument. Because essays are essentially linear—they offer one idea at a time—they must present their ideas in the order that makes most sense to a reader. Successfully structuring an essay means attending to a reader's logic.
The focus of such an essay predicts its structure. It dictates the information readers need to know and the order in which they need to receive it. Thus your essay's structure is necessarily unique to the main claim you're making. Although there are guidelines for constructing certain classic essay types (e.g., comparative analysis), there are no set formula.
Answering Questions: The Parts of an Essay
A typical essay contains many different kinds of information, often located in specialized parts or sections. Even short essays perform several different operations: introducing the argument, analyzing data, raising counterarguments, concluding. Introductions and conclusions have fixed places, but other parts don't. Counterargument, for example, may appear within a paragraph, as a free-standing section, as part of the beginning, or before the ending. Background material (historical context or biographical information, a summary of relevant theory or criticism, the definition of a key term) often appears at the beginning of the essay, between the introduction and the first analytical section, but might also appear near the beginning of the specific section to which it's relevant.
It's helpful to think of the different essay sections as answering a series of questions your reader might ask when encountering your thesis. (Readers should have questions. If they don't, your thesis is most likely simply an observation of fact, not an arguable claim.)
"What?" The first question to anticipate from a reader is "what": What evidence shows that the phenomenon described by your thesis is true? To answer the question you must examine your evidence, thus demonstrating the truth of your claim. This "what" or "demonstration" section comes early in the essay, often directly after the introduction. Since you're essentially reporting what you've observed, this is the part you might have most to say about when you first start writing. But be forewarned: it shouldn't take up much more than a third (often much less) of your finished essay. If it does, the essay will lack balance and may read as mere summary or description.
"How?" A reader will also want to know whether the claims of the thesis are true in all cases. The corresponding question is "how": How does the thesis stand up to the challenge of a counterargument? How does the introduction of new material—a new way of looking at the evidence, another set of sources—affect the claims you're making? Typically, an essay will include at least one "how" section. (Call it "complication" since you're responding to a reader's complicating questions.) This section usually comes after the "what," but keep in mind that an essay may complicate its argument several times depending on its length, and that counterargument alone may appear just about anywhere in an essay.
"Why?" Your reader will also want to know what's at stake in your claim: Why does your interpretation of a phenomenon matter to anyone beside you? This question addresses the larger implications of your thesis. It allows your readers to understand your essay within a larger context. In answering "why", your essay explains its own significance. Although you might gesture at this question in your introduction, the fullest answer to it properly belongs at your essay's end. If you leave it out, your readers will experience your essay as unfinished—or, worse, as pointless or insular.
Mapping an Essay
Structuring your essay according to a reader's logic means examining your thesis and anticipating what a reader needs to know, and in what sequence, in order to grasp and be convinced by your argument as it unfolds. The easiest way to do this is to map the essay's ideas via a written narrative. Such an account will give you a preliminary record of your ideas, and will allow you to remind yourself at every turn of the reader's needs in understanding your idea.
Essay maps ask you to predict where your reader will expect background information, counterargument, close analysis of a primary source, or a turn to secondary source material. Essay maps are not concerned with paragraphs so much as with sections of an essay. They anticipate the major argumentative moves you expect your essay to make. Try making your map like this:
- State your thesis in a sentence or two, then write another sentence saying why it's important to make that claim. Indicate, in other words, what a reader might learn by exploring the claim with you. Here you're anticipating your answer to the "why" question that you'll eventually flesh out in your conclusion.
- Begin your next sentence like this: "To be convinced by my claim, the first thing a reader needs to know is . . ." Then say why that's the first thing a reader needs to know, and name one or two items of evidence you think will make the case. This will start you off on answering the "what" question. (Alternately, you may find that the first thing your reader needs to know is some background information.)
- Begin each of the following sentences like this: "The next thing my reader needs to know is . . ." Once again, say why, and name some evidence. Continue until you've mapped out your essay.
Your map should naturally take you through some preliminary answers to the basic questions of what, how, and why. It is not a contract, though—the order in which the ideas appear is not a rigid one. Essay maps are flexible; they evolve with your ideas.
Signs of Trouble
A common structural flaw in college essays is the "walk-through" (also labeled "summary" or "description"). Walk-through essays follow the structure of their sources rather than establishing their own. Such essays generally have a descriptive thesis rather than an argumentative one. Be wary of paragraph openers that lead off with "time" words ("first," "next," "after," "then") or "listing" words ("also," "another," "in addition"). Although they don't always signal trouble, these paragraph openers often indicate that an essay's thesis and structure need work: they suggest that the essay simply reproduces the chronology of the source text (in the case of time words: first this happens, then that, and afterwards another thing . . . ) or simply lists example after example ("In addition, the use of color indicates another way that the painting differentiates between good and evil").
Copyright 2000, Elizabeth Abrams, for the Writing Center at Harvard University