A topic sentence is the main idea of a paragraph. Each paragraph contains information about one idea, and the topic sentence introduces what that idea is. The other sentences in the paragraph are the details about the main idea.
While the topic sentence is usually the first sentence in a paragraph, there can be many exceptions to this trend depending on several factors. If the paragraph is the introduction to an essay, the topic sentence does double-duty as both the thesis statement and the topic sentence. In this case, the sentence is often at the end of the paragraph. The placement of the topic sentence may also be important depending on the effect you wish to achieve or the organization you are using for an argument. If you start a paragraph with general ideas and you want to explain the role of a specific point, your organization may logically place the topic sentence at the end of the paragraph.
Here are some examples of topic sentences, highlighted in bold in each paragraph below:
- While the topic sentence is usually the first sentence in a paragraph, there can be many exceptions to this trend depending on several factors. If the paragraph is the introduction to an essay, the topic sentence does double-duty as both the thesis statement and the topic sentence. In this case, the sentence is often at the end of the paragraph. The placement of the topic sentence may also be important depending on the effect you wish to achieve or the organization you are using for an argument. If you start a paragraph with general ideas and you want to explain the role of a specific point, your organization may logically place the topic sentence at the end of the paragraph.
- Starting next week, all construction projects seeking certification under the Leadership in Energy and Environmental Design, or LEED, must use a new version of the green building standard. One of the biggest changes to LEED with the new version has to do with energy reporting — building owners must now annually submit data about how much energy (and water) they use or get recertified every two years. The new requirements aren't perfect, and the standard' approach to building energy use has some critics, but companies developing energy-related technologies for buildings could see some increased demand for their products. (Moresco, Salon, 2009 Jun 28)
- The first thing everyone notices and best remembers about "The Cabinet of Dr. Caligari" (1920) is the film's bizarre look. The actors inhabit a jagged landscape of sharp angles and tilted walls and windows, staircases climbing crazy diagonals, trees with spiky leaves, grass that looks like knives. These radical distortions immediately set the film apart from all earlier ones, which were based on the camera's innate tendency to record reality. The stylized sets, obviously two-dimensional, must have been a lot less expensive than realistic sets and locations, but I doubt that's why the director, Robert Wiene, wanted them. He is making a film of delusions and deceptive appearances, about madmen and murder, and his characters exist at right angles to reality. None of them can quite be believed, nor can they believe one another. (Ebert, 2009 Jun 3)