What is true about topic sentences?

What is a topic sentence? A topic sentence is the most important sentence in a paragraph. Sometimes referred to as a focus sentence, the topic sentence helps organize the paragraph by summarizing the information in the paragraph. In formal writing, the topic sentence is usually the first sentence in a paragraph (although it doesn't have to be). Keep reading for the two main parts of a topic sentence as well as topic sentence examples in different subjects.

Advertisement

Purpose of a topic sentence

On the surface, the purpose of a topic sentence is merely to present the main idea of the paragraph so that the reader knows what to expect. However, the best topic sentences do a little more.

First, topic sentences string together paragraphsin a way that progresses nicely and facilitates reading. Moving from one paragraph to another can feel jarring and abrupt, so topic sentences help maintain the flow of the overall piece of writing—and readers’ focus as a result.

Moreover, topic sentences also “preview” what the reader can expect from the rest of the paragraph. Based on the topic sentence, the reader can figure out if the paragraph will contain a list, statistical data, anecdotal evidence, persuasive opinions, a narrative, or something else.

If the same paragraph covers opposing points of view, you may need two or more topic sentences to show the reader the main idea has changed. The most common example of this is in paragraphs that compare or contrast positions, in which case each perspective needs its own introduction.

For these types of paragraphs, you could introduce your first idea with the opening topic sentence, then provide one or two sentences of support, and afterward introduce a second topic sentence known as a pivot (explained below). The pivot topic sentence introduces the paragraph’s second main idea or contradicting point of view, also followed by one or two sentences of support.

Different types of essays use topic sentences differently as well. Argumentative essays and persuasive essays may have more opinionated topic sentences, whereas those in expository essays would stick to facts. Compare-and-contrast essays, which alternate between opposite sides of a topic, rely on topic sentences to ease those transitions, on top of everything else.

This is true not just for different essay types, but also different paragraph types as well. Even within the same essay, the author may switch up paragraph styles between expository, descriptive, persuasive, and narrative—in that case, each requires a slightly different style of topic sentence.

Topic sentence vs. thesis statement

If you’re also learning about how to write a thesis paper, you may get topic sentences confused with thesis statements. Basically, topic sentences introduce the main idea of a paragraph, whereas thesis statements introduce the main idea of the entire paper or essay. Both serve the same function—preparing the reader with a preview—but in different capacities.