How to structure an essay

The three parts of an essay

Think of an essay as a promise kept. The introduction makes a promise, the thesis. The body paragraphs keep it, one reason at a time. The conclusion reminds the reader that the promise was kept and why it matters.

This order exists for the reader. Someone reading your essay should never have to guess what you are arguing or why a paragraph is there. When the structure is clear, the reader can spend their attention on your ideas instead of on following you.

How to write the introduction

A good introduction moves from general to specific in three moves:

• Hook: one or two sentences that make the reader want to continue, such as a surprising fact, a short scene, or a question. "In 1818, a 20-year-old writer published a novel that still shapes how we talk about science."
• Background: the context the reader needs, such as the title and author of a text, a definition, or the two sides of a debate. Keep it brief.
• Thesis: your claim, usually the last sentence. "In Frankenstein, Mary Shelley warns that the danger of science lies less in discovery than in refusing responsibility for it."

Body paragraphs: claim, evidence, reasoning

Each body paragraph proves one part of the thesis. A reliable pattern, often taught as claim, evidence, reasoning (CER), keeps it focused:

A paragraph built this way usually has five to eight sentences. Notice that the reasoning is as long as the evidence. Students lose the most marks by dropping a quotation into a paragraph and moving on, as if the evidence explained itself.

• Claim (topic sentence): the paragraph's one point, tied to the thesis. "Victor's first failure is abandoning his creature the moment it comes to life."
• Evidence: a quotation, fact, statistic or example that supports the claim, introduced smoothly and cited. "Unable to endure the aspect of the being I had created, I rushed out of the room."
• Reasoning (analysis): two or three sentences explaining how the evidence proves the claim. "Victor judges the creature by its appearance alone. By running away, he leaves a newborn being with no guide, which sets up every crime that follows."
• Closing or link sentence: ties the point back to the thesis or leads to the next paragraph.

Transitions that connect ideas

Transitions show the reader how one idea relates to the next. Pick the word for the relationship you mean, not just to vary your wording:

• Adding a point: in addition, furthermore, also, another reason.
• Giving an example: for example, for instance, in particular.
• Showing contrast: however, on the other hand, although, yet.
• Showing cause and effect: as a result, therefore, consequently, because of this.
• Showing order or time: first, next, later, finally.
• Answering the other side: admittedly, some argue that, even so.
• Concluding: overall, in the end, taken together.

How to write the conclusion

A conclusion reverses the introduction, moving from specific back to general. Restate the thesis in fresh words, sum up how the reasons fit together in a sentence or two, and then answer "so what?": why the argument matters, what it suggests beyond the essay, or what the reader should do.

Weak ending: "In conclusion, Victor was irresponsible, and that is why Frankenstein is about responsibility." Strong ending: "Two centuries later, as scientists edit genes and build artificial intelligence, Shelley's warning still applies: the people who create something powerful owe a duty to what they create."

Avoid adding a brand new argument or evidence in the conclusion. If a point is important enough to include, it belongs in a body paragraph.

The five-paragraph essay and beyond

The five-paragraph essay is an introduction, three body paragraphs and a conclusion. It is taught in middle school because it makes the structure easy to see, and it works well for timed writing on tests.

As essays get longer, the form stretches. A research paper might have two or three paragraphs for one reason, a section that explains background, or a counterargument paragraph that states the strongest opposing view and answers it. Some reasons need more space than others, so the number of body paragraphs should follow the argument, not a formula.

Different purposes also change the order. A compare and contrast essay can go point by point (setting, then characters, then theme, comparing both works each time) or subject by subject (all of one work, then all of the other). Point by point usually makes the comparison sharper.

Common structure mistakes

These are the problems that most often make an essay hard to follow:

• A topic sentence that summarizes plot instead of making a point.
• Two or three different ideas in one paragraph. Split them.
• Evidence with no reasoning after it.
• Body paragraphs that do not connect to the thesis. If a paragraph proves something else, revise the thesis or cut the paragraph.
• A conclusion that only copies the introduction word for word.
• Transitions used as decoration, such as "furthermore" before a sentence that actually contrasts.

How to outline and check your structure

Before drafting, write a quick outline: the thesis, then one line for each body paragraph's claim and the evidence you will use. If you cannot write a claim for a paragraph, you are not ready to write it yet.

After drafting, try a reverse outline. Read only the first sentence of each paragraph. Together, those sentences should read like a short version of your argument. Then, for each paragraph, underline the claim, put a box around the evidence and highlight the reasoning. A paragraph with lots of evidence and little highlighting needs more explanation.