Understand the Main Idea and Supporting Details in Written Material
Recognizing Ideas That Support, Illustrate, or Elaborate the Main Idea of a Passage
The topic sentence of the first paragraph is shown in red.
The most important part of a paragraph is its topic sentence in which the author states the main idea of the paragraph. If read in isolation, the topic sentence would rarely be understood by the reader. The main idea needs further explanation and amplification and this support is the purpose of other sentences in the paragraph. The topic sentence states the main idea; other sentences offer more information, rephrasing, clarifications, and examples to help the reader understand the main idea. When a reader completes a paragraph, the topic sentence should express its full meaning without additional explanation.
The topic sentence of a paragraph is usually its first or last sentence. Sometimes, it may be differently located, but in every case the topic sentence of a well-written paragraph will be recognized as the basic idea of it. All other sentences will further explain or clarify some portion of the topic sentence.