Writing Your Own Main Idea Sentence

Combine the topic with what the author says about it to write a clear main idea.

When a main idea is implied, or you want to put it in your own words, use a simple formula: topic + what the author says about it = main idea. First, name the topic in a word or phrase. Next, ask, 'What is the author's point about this topic? ' Then join them into one complete sentence. Try it on this paragraph: 'Long ago, sailors used the stars to find their way. Later, they used compasses.

Today, ships rely on satellites to know their exact location. ' Topic: how sailors navigate. The author's point: the tools have changed over time. Main idea: 'The tools sailors use to navigate have changed a lot over time. ' Finally, reread the paragraph and check that every detail fits under your sentence. If one doesn't, adjust the wording.

• 1Topic + the author's point = main idea.
• 2Write it as one complete sentence.
• 3Reread to check every detail fits.