All compositions are composed of literary units called paragraphs. The purpose of a paragraph is to carefully explain and develop a given idea or topic that is a part of a paper's thesis. Each unit is then segmented into a variety of sentences which are used to develop the main idea of the paragraph. Almost always, paragraphs need a central sentence called the topic sentence. This sentence tells the reader exactly what subject he or she will expect to find in the rest of the paragraph. The topic sentence is very helpful in writing unified paragraphs because it serves as a fixed idea to which all the other sentences must relate. The topic sentence is usually the first sentence, although it does not necessarily have to be placed at the beginning of the paragraph. It can also be used in the middle or at the end of a paragraph. What matters is that the total content and structure of the paragraph should be firmly rooted in the topic sentence. Here is an example of a paragraph with a topic sentence stated at the beginning. The subject is "fixing bicycles": There is a lot of work involved in fixing bicycles. First, it is necessary for one to become familiar with the structure and parts of the vehicle. Second, one must have the correct tools to make the necessary repairs. Third, the person making the repairs must prepare him or herself to put a lot of time and effort into the job and only expect minimal results at the end. Here is an example of a paragraph with the topic sentence stated in the middle. The subject is "writing a good paper": For years I have struggled with my writing skills. My inability to master correct grammar as well as my struggle to formulate coherent ideas have made my compositions very dull and ineffective. This year, however, I decided to visit the Writing Center to help improve my skills. I found, to my surprise, that the real key to writing a good paper is to have a passion for the things about which you are writing. When a person becomes interested in his or her subject of composition, he or she will make a better attempt at organizing ideas and giving them a strong coherence. Here is an example of a paragraph with the topic sentence found at the end. The subject is "cancer affects everybody": My grandfather contracted lung cancer a few months ago. The doctors now say that he only has a few weeks to live. My family's situation is not unique. Millions of Americans are going through a similar experience. At least three members of every extended family will contract terminal disease before the age of sixty. At least one out of every three nuclear families will have a member who will die of cancer before the age of fifty. From these statistics and from personal experience it is evident that no one is unaffected by cancer.
The Topic Sentence
A topic sentence usually comes at the beginning of a paragraph; that is, it is usually the first sentence in a formal academic paragraph. (Sometimes this is not true, but as you practice writing with this online lesson site, please keep to this rule unless you are instructed otherwise.) Not only is a topic sentence the first sentence of a paragraph, but, more importantly, it is the most general sentence in a paragraph. What does "most general" mean? It means that there are not many details in the sentence, but that the sentence introduces an overall idea that you want to discuss later in the paragraph. For example, suppose that you want to write a paragraph about the natural landmarks of your hometown. The first part of your paragraph might look like this:
| My hometown is famous for several amazing natural features. First, it is | |noted for the Wheaton River, which is very wide and beautiful. Also, on the other | |side of the town is Wheaton Hill, which is unusual because it is very steep. |
(Notice how the first sentence begins with "My hometown..." a few spaces to the right of the paragraph edge. This is an indentation. All...