Final answer:
A topic sentence expresses the main idea of a paragraph and guides the reader. It is usually presented at the beginning of the paragraph.
Step-by-step explanation:
A topic sentence expresses the main idea of a paragraph. It is usually presented at the beginning of a paragraph and gives the reader an overview of what the paragraph will discuss. The purpose of a topic sentence is to guide the reader and unify the overall theme of the paragraph.
For example, in an essay about the benefits of exercise, a topic sentence could be: "Regular physical activity offers numerous advantages for both physical and mental health." This sentence introduces the main idea of the paragraph and sets the tone for the subsequent supporting details.
It is important for a topic sentence to be clear, concise, and relevant to the main topic of the paragraph. It helps the reader understand the purpose of the paragraph and aids in organizing the ideas presented.
Learn more about Topic sentence