Constructing a topic sentence

Just as a thesis statement is important to convey the focus of an essay, a topic sentence is important to convey the focus of each paragraph. A topic sentence is a single, well defined idea which is supported by specific details in the rest of the paragraph.

Read the following paragraphs and the comments against each of them to get an idea of how important topic sentences are.

Paragraph without a topic sentence

Paragraph with a topic sentence

You can see that in developing your essay, merely providing details as in the first paragraph is insufficient. Instead, you need to state the focus of each paragraph clearly in a topic sentence, as in the second one.