A topic sentence clearly defines and delineates the subject matter of a paragraph. The goal of the topic sentence is to tell the reader what to expect from the paragraph, or from the next few paragraphs. Writing a topic sentence that properly conveys the main idea of your paragraph is an essential skill for a writer.

Step 1

Summarize the topic of the paragraph. For example, if the paper is about sports cars and the paragraph is about the care and maintenance of sports cars, write a topic sentence such as "Sports cars require specific care and precise maintenance to keep them running well."

Step 2

Write a topic sentence to cover multiple paragraphs. Not every paragraph will have a topic sentence. You may write a sentence that serves as the topic sentence for several related paragraphs. For example, in the article about sports cars, write the topic sentence "Sports cars require maintenance such as oil changes, tire rotation and fuel replacement at regular intervals." This sentence serves as the topic sentence for the next three paragraphs -- one on each of the maintenance aspects of sports cars.

Step 3

Place the topic sentence near the beginning of the paragraph. While the topic sentence doesn't need to be the first sentence of the paragraph in every instance, it should appear early in the paragraph to convey the subject matter as quickly as possible.