How Can I Locate the Main Idea?

Once you can find the topic, you are ready to find the main idea. The main idea is the point of the paragraph. It is the most important thought about the topic.

To figure out the main idea, ask yourself this question: What is being said about the person, thing, or idea (the topic)?

The author can locate the main idea in different places within a paragraph. The main idea is usually a sentence, and it is usually the first sentence. The writer then uses the rest of the paragraph to support the main idea.

Let’s use the paragraph below as an example. First find the topic, then look for the main idea.

Summer is a wonderful time to spend at West Beach. It is a beach with light- colored, soft sand. The coastline goes on for a long way and many people enjoy walking along it. Children like to play in the surf and walk along the rocks that are visible at low tide. This is a fun beach for people of all ages.

In this paragraph:

• the topic is West Beach
• the main idea (what the writer is saying about the topic) is that summer is a wonderful time at West Beach

Here is another example:

The movie Apollo 13 was a blockbuster for the summer of 1995. It is an exciting story about space exploration. In the movie, the astronauts get in trouble while they are trying to return to Earth. People in the audience are on the edge of their seats waiting to see what happens. What makes it even more exciting is that it is a true story. 

In this paragraph:

• the topic is the movie Apollo 13
• the main idea is in the first sentence: Apollo 13 was a blockbuster for the summer of 1995

While the main idea is usually in the first sentence, the next most common placement is in the last sentence of a paragraph. The author gives supporting information first and then makes the point in the last sentence.

Here’s a paragraph we can use as an example. Try to locate the topic and the main idea.

Most teenagers and young adults do not know what they want to do for the rest of their lives. It is a big decision. There are a number of things you can do to narrow the choices. For example you can take an interest test, do some research on your own about a career, try volunteer work in the field in which you are interested, or “job-shadow”, in which you spend a day with a person who is working in a field that interests you. These are just a few helpful ideas as you begin to choose a career. 

In this paragraph:

• the topic is jobs or career choices
• the main idea is a few ideas to help the reader choose a career

Finally, an author might put the main idea in the middle of a paragraph. The author will spend a few sentences introducing the topic, present the main idea, then spend the rest of the paragraph supporting it. This can make the main idea more difficult to find.

See if you can find the topic and main idea in the paragraph below.

The United States seems to be in love with the idea of going out to eat. Because of this, a real variety of restaurants has come about specializing in all kinds of foods. McDonald’s is the king of a subgroup of restaurants called fast-food restaurants. Chances are, no matter where you live, there is a McDonald’s restaurant near you. There are even McDonald’s in the Soviet Union. Now McDonald’s is trying something new. It is called McDonald’s Express and there is a test site in Peabody, Massachusetts. It is part of a Mobil gas station. This allows you to fill up with gas and fill up on food at the same time. What will they think of next?

In this paragraph:

• the topic is McDonald’s 
• the main idea is in the middle of the paragraph, in the third sentence: McDonald’s is the king of fast food

Excerpted from:
Study Skills: A Landmark School Student Guide (out of print)
by Diane Vener, © 2002 Landmark School, Inc.