The main idea of a paragraph is stated in one sentence. It sums up the idea of the whole paragraph. We constantly have to ask “What is the author`s main point?”
Consider the paragraph below.
Consumers concerned about the hazards or noise can reduce noise pollution in many ways. They can purchase noisy products such as garbage disposals and lawn mowers with reduced noise levels. They can also use sound-absorbing materials in their home. Carpeting can be installed instead of hard flooring, and cork and fabric can be used in rooms that tend to be noisy. Also, people can become less noisy themselves. They can learn to avoid shouting, to close doors without slamming them, and to play radios, TV sets, and stereos at moderate levels.
The topic of this paragraph is noise pollution.
The main idea is how to reduce noise in the home
The topic sentence is Consumers concerned about hazards or noise can reduce noise pollution in many ways.