As you may have read in one of our previous entries, a topic sentence is the part of a paragraph that contains the main idea of it. The rest of the information in the paragraph develops and supports this idea. The topic sentence usually includes two elements: the subject and the controlling idea. The former refers to the general topic we are talking about, and the latter is the specific aspect of the subject that the writer wants to develop in the rest of the paragraph.
The controlling idea could be a noun in the plural form which the writer could refer to throughout the paragraph, for instance, precautions, advantages, reasons, causes, effects, steps, ways, methods, types, characteristics, etc. An example of this is the topic sentence: “Learning a foreign language has several advantages” in which the subject is learning a foreign language and the controlling idea is the word advantages.
However, the topic sentence does not necessarily have to be one statement. Instead, it can be expressed in different ways. In this article, you will find examples of how the topic sentence mentioned above could be stated otherwise.