Pearson Adult Learning Centre HomePearson Adult Learning Centre: Defining the Topic Sentence



How easily can we find and define a topic sentence inside an existing paragraph? A GED instructor working at the Helping Up Mission of Baltimore hoped to find out.

Using two paragraphs taken from her students' GED text, Jeannette tried, with the help of her students, to define their "true" topic sentences. The class didn't all agree so, she sought, through an email request, to obtain expert opinions.

But, the experts don't all agree!

The comments below include those of high school teachers, university professors, professional editors, writers, and the students themselves. We at PALC hope you enjoy the collaboration.

Jump to the Expert's Answers

Instructor's Comment:

At first, I was concerned that presenting these various replies back to the guys would confuse and frustrate them because there was clearly not one *right* answer that came from the 'experts.' However, it had the opposite effect. When the guys read how each of the experts reasoned through the question and how that reasoning resulted in various conclusions, the guys felt more confident in their abilities to reason things through. Hopefully this learning experience is one that others can have through the PALC website. —Jeanette, GED Instructor at the Helping Up Mission

Editor's Comment:

On behalf of our company, I would like a note of clarification before you move on to other subjects. The lessons in the book were not chosen to model the best writing, nor did these lessons ever ask students to identify a topic sentence. Jeanette, as good teachers often do, took the lesson one step further with very interesting results.

And I do want to point out that our goal at Critical Thinking was to present writing in the Editor-in-Chief series that might actually have been done by students and to ask them to edit writing they themselves could have produced. There is no claim to model either academically perfect writing or the best topic sentences. Based on the enthusiastic editing done by the experts, I'd say the books are accomplishing their major goal.—Linda Barbour, Critical Thinking Books & Software.

The Two Paragraphs

All the answers below refer to a paragraph on the Venus's flytrap and a second paragraph on fingerprints.


Experts Answers to the Topic Sentence Question


Brad Hyde and L Yeo, Teachers at the Pearson ALC

Brad's English 10 class

Diane Nickols, Director Training and Development, MedQuist MidAtlantic Author of the upcoming MedQuist online training module on grammar and punctuation.

Former New York publishing house editor.

Jeanette's Class, Students at the Helping Up Mission.

Lady Falls Brown, Director, University Writing Center, Texas State University.

Linda Barbour of Critical Thinking Books and Software.

Mary Mashburn, Journalist and Assistant Editor, Johns Hopkins Magazine.

Mike Palmquist, Professor of English, Colorado State University

Megan Garcia, Sprague High School, Salem, Oregon



Return to top


Paragraph 1

(1) Deep in the bogs of the coastal North and South Carolinalurks an unusual plant, the Venus’s flytrap. (2) The bogs provide damp soil, but the soil lacks the nitrogen that the plant needs to survive. (3)The Venus's flytrap has developed a unique way of getting this essential nutrient. (4) Its hinged leaves have bristled edges and sensitive hairs on the insides. (5) When prey touches the hairs, the leaf closes quickly. (6) The struggling victim is trapped as the carnivorous plant secretes fluids to digest the insect and get the needed nitrogen.

(Reproduced by permission of Critical Thinking Books & Software, 800-458-4849, All Rights Reserved)

Questions for Discussion:

1. Which sentence is the topic sentence for Paragraph 1? How do you know? Write down your reasons for choosing this sentence.

2. Now, look carefully at the other sentences in the paragraph.


Paragraph 2

(1) Have you ever heard that no two fingerprints are alike? (2)Each fingerprint is made up a pattern of ridges that vary in number, size, and location. (3) There are three basic patterns of fingerprints: loops, whorls, and arches. (4) The most commonly occurring of the three patterns is the loop. (5) A loop must have one ridge that enters from one side, curves around, and exits from the same side. (6) Whorls involve ridges that curve in a circular pattern. (7) The arch, the least common pattern, is formed by ridges that enter from one side, rise in the middle, and then exit.

(Reproduced by permission of Critical Thinking Books & Software, 800-458-4849, All Rights Reserved)

Questions for Discussion:

3. Which sentence is the topic sentence for Paragraph 2? How do you know? Write down your reasons for choosing this sentence.

4. Now, look carefully at the other sentences in the paragraph.

Return to top


Answers from Brad's Grade 10 English Class:

A topic sentence is a sentence which states the main idea and usually comes at the beginning of a paragraph. (student definition)

Kevin says: The main idea in the paragraph is identified in the topic sentence and the other sentences support or explain that idea.

Brad says: Paragraphs are of limited length (sometimes only one sentence) and so can contain limited contents.

Paragraph 1

Sentence 1 (5 groups) The controlling word  is "unusual." If you choose sentence 1, then all the other sentences act to support the idea of "unusualness." This is fairly easily supported by looking at the other sentences for unusual kinds of facts.

Sentence 3 (5 groups) The controlling word is "unique." If you choose sentence 3 you are saying the idea of "uniqueness" is supported by the other sentences. Uniqueness is a part of the sentences which follow sentence 3, but Debbie raises the point that the sentence refers to sentence 2 ("this nutrient") and so requires a second sentence in order for it to work.

BUT, sentence 3 is very much like a topic sentence and mostly meets the requirements.

There is a sense of a "paragraph inside a paragraph" here with sentences 3 through 6 making almost a good paragraph without sentences 1 and 2.

Based on good practice this paragraph is not concluded for its main idea.

Paragraph 2:

Sentence 1 (5 groups) Some groups don't like the question as a topic. It argues that "no two fingerprints are alike." But the rest of the paragraph is more on what they are like. This sentence, however, is attractive and interesting and inviting—a hook, in other words.

Sentence 2 (3 groups) This sentence is more closely connected to the ideas that follow. The "what" do the fingerprints look like.

Sentence 3 (2 groups) This sentence would be a good, solid topic sentence for the details that follow. It is a kind of subtopic topic sentence or a narrowing. This paragraph has no clear concluding sentence either for the topic or subtopic. It ends.

Return to top


Linda Barbour (Comments from the Publisher):

Your discussion makes very good sense. Please congratulate your students for having thought about these matters thoroughly. If the passages you've quoted here were part of a longer essay, chapter, or book, they would separate into several or many paragraphs, each with its own topic sentence (such as the very ones you and your students have suggested), but in shorter articles, there may be several potential topic sentences in one paragraph. The paragraphs are a part of a general but brief introduction designed to cover a lot of ground without focusing in on any particular details.

I wouldn't count the students' choices as wrong in this case; however, in the first example, sentence one introduces the unusual plant and tells how and why it is unusual. Everything in the paragraph follows from that sentence even though most of the paragraph deals with how the plant gets nitrogen. You could argue for sentence three, but it lose the reader without sentence one.

The second example starts with a rhetorical question. Rhetorical questions can be topic sentences. They're just one way to grab the reader's attention while introducing the topic. In this case everything that follows in the paragraph describes the specific ways that fingerprints differ. The three classifications are, in this case, used as supporting details.

I hope I'm being clear. Just to be sure, I checked a few sources. If you want to discuss the topic of topic sentences with me some more, please feel free to e-mail or call.

Linda L. Barbour, Ph.D. 
Education Specialist
Critical Thinking Books & Software

Return to top


Diane Nickols (MedQuist MidAtlantic)

In the first paragraph, sentence #3 is the topic sentence; however, it is missing one ingredient, and that is the "nitrogen" factor. Had the word "nitrogen" been introduced in sentence #3, then that sentence #3 would have been a perfect topic sentence. Topic sentences don't necessary start paragraphs, and that would have been a good example of that. Although imperfect, sentence #3 is the topic sentence in the first paragraph. That is my opinion, although imperfect, I'm sure.

In paragraph two, the topic sentence is sentence #2. Why notsentence #3? Because sentence #2 beats #3 to the punch by using the phrase "pattern of ridges." That beats a pair, and a pair beats a flush, and a flush is something that trumps everything only in the bathroom. If you had sentence #1 (the rhetorical emotionally charged question) followed by sentence #3 without sentence #2 first, you would be buggered and lost. That is the *logistical* reason why sentence #2 and not #3 is the topic sentence. Do I get part of your pay now?

From Diane Nickols, Director Training and Development,MedQuist MidAtlantic. Author of the upcoming MedQuist online training module on grammar and punctuation.

Return to top


From a former New York Publishing House Editor

Paragraph 1

I have to definitely go with sentence 1 being the topic sentence. I think the topic simply is the Venus flytrap. Sentence 1 introduces us to this plant and the rest of the sentences provide us with a detailed description of how it survives, what it looks like and how it traps its insect victims. While sentence 3 does describe the unique way the plant gets nitrogen that it needs for survival, its wording falls short in making it a topic sentence. If sentence 3 read "The Venus's flytrap has developed a unique way of getting nitrogen, an essential nutrient for its survival," then it would be topic sentence.

Paragraph 2

Just to be difficult "why can't sentence 1 be the topic sentence"?

Well, with everyone against it, my next choice is "2." You could start off with Each fingerprint....then go to have you ever heard....then there are three basic patterns....etc.

I think 2 is a better umbrella topic than three because 2 outlines that the pattern of ridges is what makes fingerprints distinct. 3 then goes on to describe the patterns that make up the ridges. At least, that is the way I see it.

Hope this helps and does not just increase the confusion.

Return to top


Megan Garcia, Sprague High School, Salem Oregon

I am one of the crew of the online school you sent the email to re the topic sentence question--and an English teacher--so Jim sent this on to me. Now I am not an expert on topic sentences--find them usually a boring topic to teach with little reward--but I'll give this a shot.

In paragraph one, I would go with the first sentence, since the word "unusual" implies some facet that unexpected. And I would put meat-eating in that category. Sentence 3 uses "this essential nutrient" which refers to only one part of being unusual--the configuration of the leaf (being hinged)-which again fits under the category of unusual. At least in my opinion.

Now to paragraph 2-- I'd go with sentence 3, since the paragraph doesn't really develop how the patterns differ as in the rhetorical question. I'd disagree that a topic sentence cannot be a question. However, in this case, I would agree with you.

Return to top



I can probably confuse things a little more. To begin with, not all writers "professional" or otherwise, write according to the principles we teach, so poorly organized paragraphs are seen even in published materials, some of them school texts.

The two paragraphs you send, in my analysis, have a couple of problems: each lacks a topic sentence that includes the central subject of the paragraph, though they do introduce a general subject. Having the main idea in a transition sentence can be OK, but it must be handled well in order to not confuse a reader.

But the biggest problem in these paragraphs, and one that is the most difficult for young writers to master, is the use (non-use) of transitions; they are missing in key places in both paragraphs. I think you could extend the lesson by asking your students what they could do with transitions to make the topic clearer and better interrelate the ideas within the paragraphs, or to help lead the reader logically from one idea to the next.

You could also ask how they would rewrite the paragraphs (or topic sentences) to make the topic clearer. I expect there are lessons on the Internet relating to transitions.

It looks like you are doing a great job of making your students think about the impact of the way people express their ideas. The responses you listed were insightful. Hats off to you and your group of learners.

Return to top


Mike Palmquist, Professor of English, Colorado State University

Thanks for livening up my morning. I'm chuckling a bit as I write this, partly because you've given me a good puzzle and partly because I think that the dictum that every paragraph has a (single) topic sentence is a great example of what's wrong with prescriptive grammars. I'll bet that we could find plenty of paragraphs written by award-winning authors that don't fit the standard "every paragraph will have a topic sentence" rule.

In general, I think the simplest solution for paragraph one is to put a new paragraph break after the second sentence. That's probably not what you want to hear, so let me offer this suggestion. This is an example of a paragraph that doesn't have a single topic sentence. Sentences 1 and 3 offer two important ideas and the paragraph, as it stands, wouldn't work without both of them. If I wanted to revise the paragraph to make it have a single topic sentence, I'd revise it as follows:

Deep in the bogs of the coastal North and South Carolina lurks an unusual plant, the Venus’s flytrap, which has developed a unique way of getting an essential nutrient.

I might even go so far as to identify the nutrient as nitrogen, but that might pack too much info into the topic sentence.

The second paragraph uses its first sentence as an attention getter. This sentence doesn't really offer any new information, beyond the notion that no two fingerprints are alike. Of course, plenty of them are alike, but none are identical (except for those belonging to twins), so the sentence isn't exactly accurate. I think that the function of sentence one isn't so much to provide information, though, as it is to orient the reader's attention to the ideas that will follow. In this case, as you surmised, the second sentence is a topic sentence.

Thanks for a fine question. Have a great weekend and best of luck with your teaching.

Return to top


Lady Falls Brown, PhD, Director, University Writing Center, Texas State University.

According to a variety of composition texts I've used over the years, topic sentences can appear at the beginning of the paragraph (deductive), as the second sentence of the paragraph, in the middle, at the end (inductive organization), or be implied. Thus, I think the most valuable aspect of the class's study of the paragraphs in question is that the students are conscious of the role a topic sentence can play in a paragraph.

The examples on our website do put a topic sentence at the beginning of the paragraph to indicate the subject and focus of the paragraph. Much of academic writing follows this convention. I'm currently using the Allyn & Bacon Guide to Writing, and in the chapter on classical argument, the authors suggest that a claim appear in the introduction and that the claim be supported by reasons which appear as points at the beginning of each paragraph. Sounds like topic sentences to me.

Creative writers sometimes resist putting topic sentences at the beginning of paragraphs, preferring to develop a paragraph that implies the topic. The discussion can be further complicated by whether the essay follows an open form (exploratory) or a closed form (argumentative), ideas also taken from Allyn & Bacon Guide to Writing.

Now, in terms of the paragraphs, if one defines a topic sentence as indicating the subject and focus of the paragraph:

"Deep in the bogs of the coastal North and South Carolina lurks an unusual plant, the Venus’s flytrap."—this sentence indicates that the focus of the paragraph will be the Venus's flytrap and the focus is that it is unusual. The rest of the paragraph supports this idea with particulars (evidence).

"Have you ever heard that no two fingerprints are alike?"

In this sentence, the topic is fingerprints and the focus is that they differ. The second sentence clarifies the cause of the difference—the fact that the pattern of ridges vary in number, size, and location. Perhaps these sentences together indicate the subject and then the focus.

I use the examples of the website to provide ways of thinking for writers rather than as absolutes.

Please note that I do not consider myself an authority at all on the issue of topic sentences.

Return to top


Mary Mashburn, Journalist and Assistant Editor, Johns Hopkins Magazine

Totally fun!

I love that you all really debate it through-- great for reasoning and logic skills too.

For paragraph 1 I'd go with sentence three -- sentence one seems to set the scene, but doesn't give the main idea -- that the flytrap needs a specific nutrient and has developed a way to cope-- and sentence three does that. Paragraph seems to be more about the plant and its unique coping mechanism and less about how it lives in the bogs of the south.

For paragraph 2, I'd say definitely 2, which introduces the idea of varied patterns of ridges, and then 3 explicates what those patters are -- a natural follow from sentence 2.

Return to top


Brad Hyde and L Yeo, Teachers at the Pearson ALC

Thanks for you faith in our expertise. I ran this by one of our other teachers, a grammar expert who comes to us from Malaysia (and attended university in Edinburgh). We are both in agreement that the first sentences in each case are the true topic sentences.

What might be confusing is that "topic-like" sentences do occur inside paragraphs, especially when covering multiple or complex topics. Each new idea, then, might require an introducing sentence that functions in a very similar fashion to a topic sentence.

Specifically, in Paragraph 1, the key and controlling word is "unusual." The other details all support the idea of unusualness. No, the first two sentences are not background, but are at a higher level of generality than the details that follow. This is quite normal, actually. Tell your class that they are asking the right questions, however!

In Paragraph 2, the key and controlling idea is "unlike." The "patterns" are indeed unlike each other, so the details do fit to the main, topic sentence idea. I would agree that the rhetorical question posed in the true topic sentence could be omitted and sentence 2 might then make a better topic sentence.

What to remember (or learn from all this) is that paragraphs are unique constructs and can vary from the established (teaching) patterns. For my students, I emphasize their writing of good topic sentences, particularly those that contain easily exemplified ideas that fit the "container" that represents the simple paragraph. Remember, too, the inductive pattern (common to science) of placing the true topic sentence at the end!

Return to top


Jeanette's Class Response

Our discussion in class went like this: The topic sentence is either sentence 1 or 3. Sentence 1 introduces the topic (Venus's flytrap); therefore, it meets the definition of the topic sentence.

However, sentence 3 introduces the main idea about which all supporting details pertain: that the plant has a unique way of getting nitrogen. Therefore, it also meets the definition of the topic sentence. Your help please?

Our discussion in class went like this: Sentence 1 is a question. Questions generally are not good topic sentences, but rather are rhetorical devices to lead the reader to the topic sentence. Therefore, we eliminated sentence 1. The topic sentence is either sentence 2 or 3.

Sentence two introduces the idea of fingerprints having patterns, and this would meet the definition of the topic sentence. All subsequent supporting details can fit under it.

However, sentence 3 discusses the three basic patterns, and all supporting details define and describe these basic patterns. Therefore, sentence 3 could easily be the topic sentence. Your help please?

Weekly Feature Index (Includes all 2005 to date Weekly Features with descriptions)