Each paragraph in your paper should begin with a topic sentence. A topic sentence announces the topic of the paragraph and presents the main idea of the paragraph. Topic sentences are important connectors as they link each paragraph to the paragraph that came before (as a transition) as well as to your paper’s overall controlling idea (thesis).
The main idea, topic sentence, should be the first sentence of your paragraph. Academic style in English presents supporting evidence for an idea after the topic sentence. In this way, you are letting your reader know the direction (or destination) of the paragraph before they read the entire paragraph. Think of your topic sentence as a directional signpost for your reader.
Knowing how topic sentences work will also help you as a reader. Your reading efficiency can be improved by previewing topic sentences; likewise, the topic sentences you write will help your reader to move easily through your paper.
•Avoid statements that announce broad topics or are too general.
• Write or revise your topic sentence after you have written the paragraph.
•Topic sentences should be carefully written and revised several times if needed.
•Make sure that the key words used in your paragraph are also present in your topic sentence.
•If you are stuck and cannot write your topic sentence, answer the following question: What is this paragraph about? Your topic sentence is the answer to this question.
Watch this 3-minute introduction to writing topic sentences.