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3.5 Topic Sentences

Erin Thomas, MFA

Why Topic Sentences?

Imagine reading one long block of text, with each idea blurring into the next. We are likely to lose interest in writing that is disorganized and spans many pages without breaks. Paragraphs separate ideas into logical, manageable chunks. By exploring one idea at a time, the writer has a chance to explain and support that idea.

The reader can then fully understand the central idea before moving on to the next paragraph. A topic sentence is a sentence that summarizes the main idea of a paragraph, just as a thesis summarizes a whole essay. As the unifying sentence for the paragraph, the topic sentence is the most general idea, while supporting sentences provide more specific information, such as facts, details, or examples. Each topic sentence should clearly relate to the essay’s thesis.

Effective Topic Sentences

The goal of a topic sentence is to help readers identify and remember the main idea of the paragraph. The challenge is to write a sentence that covers all the points of the paragraph, but does not contain too many words or details. Consider the examples in the box below.

Vague topic sentence: “First, we need a better way to educate students.”

Explanation: The claim is vague because it does not provide enough information about what will follow, and it is too broad to be covered effectively in one paragraph.

Revised version: “Creating a national set of standards for math and English education will improve student learning in many states.”

Explanation: The sentence replaces the vague phrase “a better way” and leads readers to expect supporting facts and examples as to why standardizing education in these subjects might improve student learning in many states.

In addition, an effective topic sentence is clear, direct, and easy to follow. It gets right to the point and doesn’t require the reader to search for the main idea.

Confusing topic sentence: “In general, writing an essay, thesis, or other academic or nonacademic document is considerably easier and of much higher quality if you first construct an outline, of which there are many different types.”

Explanation: The convoluted sentence structure and unnecessary vocabulary bury the main idea, making it difficult for the reader to follow the topic sentence.

Revised version: Most forms of writing can be improved by first creating an outline.

Explanation: This topic sentence cuts out unnecessary words and simplifies the previous statement, making it easier for the reader to follow. The writer can include examples of what kinds of writing can benefit from outlining in the supporting sentences.

Topic Sentence Placement

In academic writing, the topic sentence is usually the first sentence or second sentence of a paragraph and expresses its main idea, followed by supporting sentences that explain, prove, or enhance the topic sentence. In most college essays, placing a clear topic sentence at the beginning of each paragraph (the first or second sentence) makes it easier for readers to follow the essay and helps writers stay on topic. Ultimately, readers must be able to easily identify the main idea of the paragraph.

Sometimes, especially in narrative or creative writing, a writer may suggest or imply the topic sentence rather than stating it directly. The following examples illustrate the most common locations for the topic sentence. In each example, the topic sentence is underlined, and an explanation is provided for why the writer chose the location.

Topic Sentence Begins the Paragraph (General to Specific)

Paragraphs that begin with the topic sentence move from the general to the specific. They open with a general statement about a subject and then discuss specific examples. This is the common pattern for most academic essays.

After reading the new TV guide this week I wondered why we are still being bombarded with reality shows, a plague that continues to darken our airwaves. Along with the return of viewer favorites, we are to be cursed with yet another mindless creation. Prisoner follows the daily lives of eight suburban housewives who have chosen to be put in jail for the purposes of this fake psychological experiment. A preview for the first episode shows the usual tears and tantrums associated with reality television. I dread to think what producers will come up with next season and hope that other viewers will express their criticism. These producers must stop the constant stream of meaningless shows without plotlines. We’ve had enough reality television to last us a lifetime!

Here, the first sentence tells readers that the paragraph will be about reality television shows, and it expresses the writer’s distaste for these shows by using the word bombarded. Each of the following sentences in the paragraph supports the topic sentence with information about a specific reality television show and why the writer finds it unappealing. The final sentence is the concluding sentence. It reiterates the main point that viewers are bored with reality television shows by using different words from the topic sentence.

Topic Sentence Ends the Paragraph (Specific to General)

Sometimes, especially in persuasive writing, a writer chooses to save the most general statement for the last sentence after compiling facts and supporting details to convince the reader. By building to the topic sentence, the writer hopes to convince the readers that they are arriving at the main idea with them. The risk is that the reader will want to know where the paragraph is going sooner. In the paragraph below, the topic sentence comes last.

Last year, a cat traveled 130 miles to reach its family, who had moved to another state and had left their pet behind. Even though it had never been to their new home, the cat was able to track down its former owners. A dog in my neighborhood can predict when its master is about to have a seizure. It makes sure that he does not hurt himself during an epileptic fit. Compared to many animals, our own senses are almost dull.

In this example, explaining how a cat tracked down its owners and how a dog that can predict seizures prepare the reader for the general conclusion: animals’ senses are better than humans’.

Topic Sentence in the Middle of the Paragraph

Occasionally, a writer might choose to hook the reader or introduce a concept before providing the topic sentence in the middle of the paragraph. In the paragraph below, the underlined topic sentence expresses the main idea—that breathing exercises can help control anxiety. The preceding sentences enable the writer to build up to the main point with a personal anecdote. The supporting sentences then expand on how breathing exercises help the writer by providing additional information. The concluding sentence restates how breathing can help manage anxiety.

For many years, I suffered from severe anxiety every time I took an exam. Hours before the exam, my heart would begin pounding, my legs would shake, and sometimes I would become physically unable to move. Last year, I was referred to a specialist and finally found a way to control my anxiety—breathing exercises. It seems so simple, but by doing just a few breathing exercises a couple of hours before an exam, I gradually got my anxiety under control. The exercises help slow my heart rate and make me feel less anxious. Better yet, they require no pills, no equipment, and very little time. It’s amazing how just breathing correctly has helped me learn to manage my anxiety symptoms.

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Attributions: Some sections of the above are original content by Anna Mills and others are adapted from the following sources: Writing for Success, created by an author and publisher who prefer to remain anonymous, adapted and presented by the Saylor Foundation and licensed CC BY-NC-SA 3.0. Successful College Composition, also licensed CC BY-NC-SA 3.0, which was itself adapted from Writing for Success. 12.2: Topic Sentences is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.

Strategies for Identifying the Topic Sentence

If you are having difficulty locating the topic sentence, you can refer to the strategies you learned to identify the main idea. Then use these simple questions as a guide to help you find the topic sentence:

  1. What is the most important word(s) in this paragraph? = the topic
  2. What does the paragraph say about this word(s)? = the main idea
  3. Which sentence explains the main idea of the paragraph best? = the topic sentence

Instructions

  1. Read the following text about the motion picture, King Kong, which debuted in 1933 during the Great Depression. Since that time, King Kong has become a cultural icon, inspiring sequels in Japan and the U.S.
  2. In this exercise, underline the sentence that “best” captures the main idea in each of the nine paragraphs.
  3. To do this, first, identify the topic, then the main idea, and then select the sentence that “best” captures the main idea. Note that the topic sentence is often the most general sentence in a text.
  4. Write the topic and main idea below each paragraph. Then underline the topic sentence.
  5. After underlining the topic sentence, explain in your own words why you selected it. The first paragraph has been completed as an example.
  6. Power Tip: In real-world text, the topic sentence can be expressed by two sentences or half of a compound or complex sentence. Also, as previously mentioned, sometimes topic sentences are implied instead of stated directly.

King Kong: The Dawning of a Legend

Figure 3.5.1: King Kong and Ann Darrow over New York City

King Kong’s Film Debut

Paragraph 1: King Kong, a fictional, ape-like monster made his first debut in Hollywood in 1933 with RKO pictures. The first showing premiered at two movie theaters, the Radio City Music Hall and the RKO Roxy Theatre. Despite the fact that the movie was released during the Great Depression, it drew thousands of viewers for 35 to 75 cents per ticket. The movie combined adventure, romance, and special effects in a way that hadn’t been attempted before. And the heroine Ann Darrow’s (Fay Wray) thin, feminine frame drew a stark contrast with King Kong, a colossal beast.  According to, “Fay Wray’s scream as the captive beauty facing Kong’s towering obsession became an indelible piece of film history.” Despite the economy, the movie made $100,000 the first weekend, finally grossing millions, which saved RKO pictures from bankruptcy. Type your textbox content here.

Topic: King Kong Movie Premiere

Main Idea: The movie premiere was extremely successful during the Great Depression because of its unique characteristics.

Reason for selecting topic sentence: In this paragraph, there isn’t a sentence that perfectly expresses the main idea, but the last sentence emphasizes the success of the film during the Great Depression.

King Kong Plot Overview

Paragraph 2: The movie begins with the exploits of film crew who voyage to Skull Island, where they come head to head with the roaring Kong, a name given to the enormous ape by the natives of the fictional island, purportedly located in the Indian Ocean. But Kong is not the only unusually sized animal. Enormous fauna are a unique characteristic of the island, and the native inhabitants have built a village within a 70 foot wall, where they worship Kong from a distance. Skull Island is also the home of plesiosaurs, pterosaurs, and various dinosaurs.

Topic:

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Paragraph 3: The American film crew, led by character, Carl Denham, captures Kong and takes him to New York City to be exhibited as the “Eighth Wonder of the World.” Kong escapes and climbs the Empire State Building, only to fall from the skyscraper after being attacked by weaponized biplanes. Denham comments, “It wasn’t the aeroplanes, it was beauty killed the beast,” because he climbs the building in the first place in an attempt to protect Ann Darrow, an actress originally kidnapped by the natives of the island and offered up to Kong as a sacrifice.

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The Creation of King Kong

Early Ideation

Paragraph 4: The King Kong character was conceived and created by American filmmaker Merian C. Cooper. He became fascinated by gorillas at the age of six. In 1899, Cooper was given a book from his uncle called Explorations and Adventures in Equatorial Africa. The book, written in 1861, chronicled the adventures of Paul Du Chaillu in Africa and his various encounters with the natives and wildlife there. Cooper became fascinated with the stories involving the gorillas, in particular, a gorilla known for its “extraordinary size,” that the natives described as “invincible” and the “King of the African Forest.”. The book described the gorilla as a “hellish dream creature” that was “half man, half beast”.Type your textbox content here.

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Paragraph 5: As an adult, Cooper became involved in the motion picture industry. While filming The Four Feathers in Africa, he came into contact with a family of baboons. This gave him the idea to make a picture about primates, which gradually evolved into the idea of a “terror gorilla” movie. When developing storyline, Cooper decided to make his gorilla giant-sized. Cooper stated that the idea of Kong fighting warplanes on top of a building came from him seeing a plane flying over the New York Insurance Building, then the tallest building in the world. He came up with the ending before the rest of the story: “I immediately saw in my mind’s eye a giant gorilla on top of the building.”  Cooper also was influenced by accounts of Komodo dragons in Indonesia and imagined battles between his mega-gorilla and dinosaur-sized reptiles. Whether King Kong was battling enormous lizards or the U.S. army, he would be the main character of the films, which would focus on the theme of “a gigantic semi-humanoid gorilla pitted against modern civilization.”

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King Kong: Half Human, Half Ape

Paragraph 6: When designing King Kong, Cooper wanted him to be a nightmarish gorilla monster. As he described Kong in a 1930 memo: “His hands and feet have the size and strength of steam shovels; his girth is that of a steam boiler. This is a monster with the strength of a hundred men. But more terrifying is the head—a nightmare head with bloodshot eyes and jagged teeth set under a thick mat of hair, a face half-beast half-human.”

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Paragraph 7: Motion picture special effects artist, Willis O’Brien, created the first version of King Kong. The oil painting depicted the giant gorilla threatening a jungle heroine and a hunter. When the sculptor, Marcel Delgado, started working on the animation model, O’Brien told him to “make that ape almost human.” He wanted King Kong to be almost human-like to gain audience empathy. Cooper laughed at the end result, saying that it looked like a cross between a monkey and a man with very long hair. For the second model, O’Brien again asked Delgado to add human features but to tone it down somewhat, which was described as looking like a missing link. Disappointed, Cooper stated, “I want Kong to be the fiercest, most brutal, monstrous damned thing that has ever been seen!”

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Paragraph 8: On December 22, 1931, Cooper obtained the dimensions of a bull gorilla from the American Museum of Natural History, telling O’Brien, “Now that’s what I want!” When the final model was created, it had the basic look of a gorilla but managed to retain some human-like qualities. For example, Delgado streamlined the body by removing the distinctive paunch and rump of a gorilla. When it came time to film, Cooper agreed that Kong should walk upright at times (mostly in the New York sequences) to appear more intimidating. [2]

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Media Attributions


  1. Mills, A. (2025, May 13). 12.2: Topic Sentences. Humanities LibreTexts. Retrieved August 9, 2025, from https://human.libretexts.org/Bookshelves/Composition/Advanced_Composition/How_Arguments_Work_-_A_Guide_to_Writing_and_Analyzing_Texts_in_College_(Mills)/12%3A_Essay_Organization/12.02%3A_Topic_Sentences
  2. Cooper, M. C. (n.d.). King Kong. Wikipedia. Retrieved August 9, 2025, from https://en.wikipedia.org/wiki/King_Kong

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