When outlining an essay, what is the purpose of a topic sentence?

• A. To provide transitions between sections.
• B. To summarize the entire essay.
• C. To introduce the main idea of a paragraph.
• D. To introduce evidence that supports the thesis.

Answer: (C)

The main idea being tested is how a topic sentence frames a paragraph. A topic sentence states the central point of that paragraph, telling the reader what argument or idea will be developed and how it connects to the overall thesis. It gives the paragraph its direction and keeps the writing focused, so the rest of the sentence and the evidence that follows can be chosen to support that specific idea. In outlining, this sentence acts as a compact guide for what the paragraph will cover, making the structure clear and cohesive.

Transitions between sections are about linking ideas from one part to the next, which can be a function of surrounding sentences but isn’t the primary job of the topic sentence. Summarizing the entire essay belongs to the conclusion (or a separate summary), not to a single paragraph’s opening. Introducing evidence happens after the topic sentence; the paragraph presents that main idea first and then provides evidence to support it.