In college writing, the abstract ideas will be found in our sentences. For every paragraph you write, you must have one sentence that contains an abstract idea that all the other sentences will explain, prove, show, or support. This main idea sentence is called the topic sentence.
In the following topic sentence, which word or phrase is abstract and needs to be explained?
Our vacation at the new resort was unpleasant.
If you said “unpleasant” is abstract, then you would be right. What is unpleasant for one person may be different for another. Therefore, it is the job of the writer to define with good examples what an unpleasant experience in a resort would be like.
Take a few minutes and write down what are unpleasant things a person might experience while vacationing at a resort. Then share with the class.
For the following group of sentences, put a P next to the point or main idea sentence that contains the abstract idea. All the other sentences should explain that abstract idea, thus support the main idea.
Ex. _______ a. The roof has holes, and bats have been seen inside the attic areas.
_______ b. The office building is not in good shape.
_______ c. There are signs of roaches in the crawl space.
_______ d. The windows are so old that cold air leaks through during the winter, making it hard for tenants to stay warm.
Which sentence in the grouping above has the abstract idea that all the other sentences explain? If you said B, then you would be correct. “Not in good shape” needs to be explained further. If you look at all the other sentences, they illustrate how the office building is in bad shape.
Writing Good Topic (Main Idea) Sentences
The topic sentence is one of the most important parts of a paragraph; the thesis is the most important sentence in an essay. It contains the controlling thought (main idea) and must lead the reader into the rest of the paper. It also should contain an abstract idea that must be explained by the subsequent supporting sentences.
Features of a Good main idea Sentence
Every good paragraph has a solid main idea sentence. The criteria listed below are essential:
- It must be a sentence in statement form. It cannot be a question.
- It must state one main idea clearly.
- It must be something that can be explained, proven, or shown.
- It must prepare the reader for the rest of the paper.
- It should have an abstract idea (controlling idea) in it.
- It should make the reader want to read the rest of the paper.
Exercise 1: Choose the main idea sentence from the four options listed below. Please explain why it is the main idea sentence based on the criteria listed above.
- Skiing in the Winter
- I ski in the winter.
- Have you ever wondered why people ski in the winter?
- There are a number of reasons why I love skiing in the winter.
Using Opening Phrases to Create the Abstract Idea in Your Topic Sentence
An opening phrase is used in many main idea sentences. The opening phrase tells the reader that a list of major details is coming. For example, a paragraph may begin with, “There are several ways residents can assist in the elimination of yard waste.” The words “several ways” suggest that what follows will be a list of the specific ways residents can assist in eliminating yard waste.
Some typical opening phrases are listed below. These might not work exactly as they are written in your topic sentence but rewording them slightly may help you develop that abstract idea.
several kinds of
a series of
four causes of
a few reasons for
three characteristics of
two advantages of
a number of steps
several reasons why
Problems with Topic Sentences
There are a few common problems students have with writing main idea sentences.
- The sentence is too broad. Sometimes the topic needs to be narrowed down to fit the assignment. Some main idea sentences are so abstract that a writer could literally write a book about that topic.
- The sentence is too narrow. This goes back to the basic criteria for a main idea sentence. The writer must be able to explain, prove, or show something about that topic. If the sentence is just a statement, then it is too narrow and therefore cannot be used as a topic sentence.
- It really isn’t a sentence at all. A lot of students put a cluster of fragmented ideas at the top of papers and call that a main idea sentence. It might serve as a title of a paper, but the main idea sentence must be a sentence, meaning it has a subject and a verb and it expresses a complete idea.
- It just announces the topic. You cannot just announce the topic. Remember that the main idea sentence contains a topic and your perspective on that topic. You can’t just say, “I am going to tell you about such and such.”