Topic Sentences

Topic sentences are the “thesis statements” of paragraphs; therefore, they are both a part of keeping the promise made by the thesis, as well as a sub-promise that should be kept by the paragraphs. They are usually the first sentence in the paragraph. The reader expects topic sentences to provide proof of one aspect of the thesis sentence as well as to provide an indication of what will follow in the paragraph.


A topic sentence is NOT simply a statement of fact. A fact does not contain any controlling ideas that can be easily explained, described, illustrated or analyzed.


There are two kinds of topic sentences:


A statement of opinion


A statement of opinion contains some form of judgment and the paragraph will support the opinion in the topic sentence.



The computer is the greatest invention of the twentieth century.


A statement of intent


A statement of intent contains no opinion; instead, it informs the reader of what will be objectively explained in the paragraph.



The common seasoning monosodium glutamate (MSG) has negative side effects.


Topic Sentence Functions

An effective topic sentence:


Relates to the thesis.

Sets up a claim, assertion, argument, evaluation, analysis.

Contains controlling ideas about the topic that need to be developed in the sentences that follow.

Is the most general sentence in the paragraph.

Orients the reader.

Provides a context for understanding what follows.

Explains the relationships among elements.

Summarizes the rest of the paragraph.

Promises what will follow.


Guidelines for Topic Sentences


A topic sentence must be a complete sentence to perform all the necessary functions.

Weak:   Some types of birth control should be provided by schools.

Better:   To prevent unwanted pregnancies and sexually transmitted diseases, schools should provide every form of non-prescription birth control available.


A topic sentence must predict or promise what follows, so it cannot be a question.

Weak:   Should schools provide free computers for their students?

Better:   Since schools should assist students in their studies and prepare them for their future careers, they must offer students the technological advantage of free and easy access to computers.


Phrases such as “I think” or “in my opinion” may muddle or weaken topic sentences. Your writing is always your opinion, so you don’t need these phrases unless they are central to the idea that you are trying to convey.

Weak:   I think that it is important for every woman to carry mace or pepper spray.

Better:   As violent criminals take over the city streets, women must carry mace or pepper spray to protect themselves.


The topic sentence should provide clear relationships among all of its elements so that it can provide a framework for understanding the rest of the paragraph.

Weak:   Historians record only dry statistics; we should read novels.

Better:   Accurate historical novels give us a deeper understanding of the past than do the dry collection of facts and statistics that pass for history texts.


A topic sentence needs to be clear and specific, so that it can predict and summarize the rest of the paragraph for the reader.

Weak:   Public transit is terrible.

Better:   Incapable of providing reliable, comfortable service, the San Francisco Municipal Transit system is failing its ridership.


A topic sentence must be coherent so that the reader can use it as a key to the rest of the paragraph.

Weak:   The differences of their socioeconomic classes, indeed, were not more potent than the already inherent differences among the population.

Better:   Bosnia is split apart not by any economic class differences, but by racial and ethnic conflicts.

Because the topic sentence is a reference for the rest of the paragraph, it needs to be exceptionally clear. If there is figurative language in a topic sentence, the wording should be such that the reader does not need to understand the allusion to understand the sentence.

Weak:   The Surgeon General must be the Hercules that slays the Hydra of chemical addictions.

Better:   As Hercules slew Hydra, the Surgeon General must defeat the many-headed monster that is chemical addiction.



Other Sentence Functions


The rest of the paragraph must:


Fulfill the promise set by the topic sentence.

Be on the same topic.

Relate to each other and the topic sentence in a manner established by the topic sentence.


Exercise:  Below is a hypothetical essay assignment. With this assignment in mind, determine if any of the topic and thesis sentences for the following three “essay skeletons” would lead to an effective essay. If not, why?


Essay Assignment:

We all have in our lives certain types of people we tend to avoid: aggressive types, “nosy” types, people who monopolize every conversation with talk about themselves, people who always seem to be bad-tempered. Identify one type of person you tend to avoid, and then, in a well-organized and well-developed essay, explain why you avoid that type of person.


Essay Skeleton # 1


Thesis:      After having dated several of them, I have discovered that I want to avoid possessive boyfriends at all costs.


Topic Sentence:  This kind of man always wants to set limits on how much time I can spend socializing with my female friends.

Topic Sentence:  Possessive boyfriends can be counted on to display annoyance whenever I talk to my other male friends.

Topic Sentence:  Besides being possessive, such males can also be incredibly stingy with money.



Essay Skeleton # 2


Thesis:      Over the years, I have learned to avoid strict teachers because they give too much homework, show no understanding when a student turns in assignments late, get impatient instead of helping when students don’t understand the subject matter, and often yell at the class.


Topic Sentence:  At age six, I entered school.

Topic Sentence:  Later on, I got into the sixth grade.

Topic Sentence:  Eventually, I went on to high school.

Topic Sentence:  Finally, I went to college.


Essay Skeleton # 3


Thesis:      Without a doubt, narcissistic people are the types most vociferously to be avoided; whenever I happen to encounter one, I will automatically try to discontinue having to have any contact with that individual.


Topic Sentence:  Narcissistic people always think that no one else could possibly be so physically stunning in appearance as they are.

Topic Sentence:  It would seem that narcissistic people would like to believe that there are no other persons in the world who could win beauty contests and attract mates as easily as they could.

Topic Sentence:  These people show in every way that they believe their beauty is more impressive than anyone else’s.



Exercise:  Now create your own topic sentences for the following thesis statement.


Thesis:      I’ve learned from experience that people who have short tempers never change, and their short tempers can end up making your life miserable.


Topic Sentence:










Topic Sentence:










Topic Sentence: