What Is a Topic Sentence? (With Examples)

A topic sentence is the sentence that states the main idea of a paragraph. It names the topic and says something specific about it, and every other sentence in the paragraph explains or supports that idea.

For example: High schools should start classes later in the morning so that teenagers can get more sleep. The topic is school start times. The point the rest of the paragraph has to back up is that a later start would be better for students.

In most essays the topic sentence is the first sentence of a body paragraph, though writing guides disagree on whether it has to be. This guide covers the three parts of a paragraph, 16 topic sentence examples sorted by essay type, how to write one in four steps, what a concluding sentence does and the PEEL and hamburger models.

The three parts of a paragraph

Most writing guides describe a body paragraph in three parts. The open textbook Writing for Success names them as "a topic sentence, body, and concluding sentence"; many teachers call the body the supporting sentences.

1. The topic sentence states the paragraph's main idea. It has two halves: the topic, and what you are saying about it. Many guides call that second half the controlling idea. The UNC Writing Center uses the same term for the paragraph's whole main idea, because it "controls what happens in the rest of the paragraph."
2. The supporting sentences give the reasons, facts, examples, quotations and explanation that show the topic sentence is true. Writing for Success says most paragraphs have three to six of them, "depending on the audience and purpose for writing." For what the guides say about length in more detail, see how many sentences are in a paragraph.
3. The concluding sentence closes the point by restating the main idea in new words. There is more on it below.

An annotated paragraph

Here is an expository paragraph written for this guide, with each sentence labeled by its job:

1. Topic sentence: A basic loaf of bread needs only four ingredients: flour, water, salt and yeast. (Topic: a basic loaf. Controlling idea: it needs only four things.)
2. Support: Flour and water form the dough.
3. Support: Yeast makes the dough rise by giving off gas as it feeds on the sugars in the flour.
4. Support: Salt adds flavor and slows the yeast down, so the dough rises steadily.
5. Support: Butter, milk, seeds and sugar can make a loaf richer, but none of them is essential.
6. Concluding sentence: With those four basics in the cupboard, you can bake a simple loaf at home.

Every supporting sentence explains one of the four ingredients or why nothing else is needed, so nothing strays from the topic sentence. The concluding sentence repeats its idea (only four things are needed) without repeating its words.

Topic sentence examples

The 16 examples below were written for this page and are grouped by the four main essay types. For each one, ask two questions: what is the topic, and what does the sentence say about it? Each type asks its topic sentence to do a different job, and our guide to the types of paragraphs, with a worked example of each shows how the rest of each paragraph follows from it.

Argumentative (persuasive) topic sentences

An argumentative topic sentence makes a claim a reasonable reader could disagree with, so the paragraph has something to prove.

• High schools should start classes later in the morning so that teenagers can get more sleep.
• Free public transit would do more to cut city traffic than building new roads.
• Banning phones in classrooms helps students more than it hurts them.
• In the opening of A Christmas Carol, Dickens presents Scrooge as a man ruled by greed.

The last one comes from a literature essay. It argues too: it makes a claim about a text that the paragraph has to prove with quotations, as in the PEEL example further down.

Expository topic sentences

An expository topic sentence states what the paragraph will explain. It does not take sides, but it still has a controlling idea: the angle the paragraph takes, or the points it will cover.

• There are three main types of rock: igneous, sedimentary and metamorphic.
• Photosynthesis is how plants use sunlight to turn water and carbon dioxide into food.
• A basic loaf of bread needs only four ingredients: flour, water, salt and yeast.
• Recycling a plastic bottle takes several steps between your bin and a new product.

The first and third also list the points to come. Nashville State Community College's ESL writing guide calls these predictors and treats them as "optional but preferred."

Narrative topic sentences

A narrative paragraph tells events in order, so its topic sentence sets up the event and often hints at why it mattered.

• The summer I spent working on my uncle's farm taught me how to keep going when I was tired.
• My first attempt at camping alone went wrong before I had even pitched the tent.
• The morning of my driving test began badly and got worse.
• Moving to a new school in the middle of the year turned out better than I expected.

Descriptive topic sentences

A descriptive topic sentence names what you are describing and the main impression you want the reader to take away.

• My grandmother's kitchen always smelled of cardamom and fried onions.
• By late October, the park near our house turns into a field of red and gold.
• The library's reading room is the quietest place I know.
• The old market on Station Road is at its loudest in the hour before it closes.

Narrative and descriptive writing is also where you are most likely to meet a paragraph with no topic sentence at all. Purdue OWL notes that "not all paragraphs have clear-cut topic sentences," and Writing for Success says leaving the main idea implied "is often used in descriptive or narrative writing." It warns against doing so in informational writing, because readers "often lose patience if they are unable to quickly grasp what the writer is trying to say." In a school essay, state it.

Stuck on the first words? Our list of topic sentence starters has ten openers, such as "One reason" and "The main cause of," each with an example sentence.

How to write a topic sentence in four steps

Start from the point the paragraph has to make, not from the first words that come to mind.

One topic sentence, revised

Here is how the four steps turn a weak opening into a usable topic sentence:

• An announcement: "In this paragraph, I will talk about phones in school." It names the topic but makes no point.
• Too broad: "Phones have changed schools." True, but far too big for one paragraph.
• A bare fact: "Many schools have rules about phones." There is nothing left to argue or explain.
• Ready to use: "Banning phones in classrooms helps students more than it hurts them." One topic, one clear claim, and a paragraph's worth of support to find.

These checks follow the rules in Nashville State's guide (a statement, not a question; no announcements; no bare facts; a narrowed topic) and in the University of New Mexico's Core Writing guide to topic sentences, which warns that a vague topic sentence can be "too broad to be covered effectively in one paragraph."

Once the topic sentence is right, the paragraph expander can grow it into a paragraph with detail, examples and reasoning, or the paragraph generator can draft a whole body paragraph in its free Body mode, which opens with a topic sentence and ties the point back to your argument. Its Introduction and Conclusion modes, also free, cover the other two parts of an essay. Check every fact either tool adds against your own sources.

What is a concluding sentence?

A concluding sentence is the last sentence of a body paragraph. It closes that one paragraph, not the whole essay. Writing for Success says a good one "reminds readers of the main point" without "restating it in exactly the same words," and that it should not bring in new ideas, because a subject the paragraph never covered will confuse the reader.

The same textbook lists five jobs a concluding sentence can do: restate the main idea, summarize the key points, draw a conclusion from the information, make a prediction, suggestion or recommendation, or offer one more observation about the controlling idea. Here are concluding sentences for four of the topic sentences above, one from each essay type:

Should a concluding sentence lead into the next paragraph?

Writing guides disagree. The UNC Writing Center lets you end on a concluding point or, as it puts it, "You might, however, simply transition to the next paragraph." PEEL guides build that forward step in: Southern Cross University's guide to body paragraphs says the final sentence should be "a concise summary of the key point" and "ideally a link to the key point of the next paragraph." Occidental College's Writing Center says the opposite: "the concluding sentence of a paragraph should not be a transition introducing the next paragraph." It puts the transition in the next topic sentence instead.

If your teacher or style guide does not say, our suggestion is to close the point first and let the next topic sentence carry the link. That way each paragraph still reads as complete on its own.

Ending a whole essay is a different job. Our conclusion sentence starters for essays and single paragraphs cover it, and if your closing lines keep opening with the same phrase, try these other ways to say "in conclusion".