What is a Topic Sentence?
A topic sentence states the main point of a paragraph. It usually comes first, tells the reader what the paragraph will show, and links that point back to the thesis statement. Every other sentence in the paragraph should support it.
Purpose of a Topic Sentence
- Focus: it decides what belongs in the paragraph.
- Signposting: readers who skim the first sentence of each paragraph can follow the whole argument.
- Connection: it shows how this paragraph advances the thesis.
What Goes in a Topic Sentence
A strong topic sentence has two parts: the topic and a controlling idea, the specific claim you will make about it. In "Online lectures increase flexibility but reduce participation", the topic is online lectures and the controlling idea is the trade-off between flexibility and participation.
Topic Sentence Examples
- Argument: "The strongest case for a four-day week comes from evidence on productivity, not well-being."
- Evidence: "Survey data from three universities show the same pattern."
- Contrast: "Critics of carbon pricing, however, point to its effect on low-income households."
- Literature review: "Studies of feedback timing fall into two groups."
Weak vs Strong Topic Sentences
- Weak: "Exercise is important." Strong: "Regular aerobic exercise reduces anxiety symptoms in students, according to most controlled trials."
- Weak: "In 1990, the law changed." (a fact, not a point) Strong: "The 1990 reform shifted responsibility for training from employers to the state."
How to Write an Effective Topic Sentence
- Decide what single point the paragraph makes in support of the thesis.
- State that point directly, with a specific controlling idea.
- Where it helps, open with a transition that shows how it relates to the previous paragraph.
- After drafting the paragraph, check that every sentence supports the topic sentence, and revise one or the other.
Common Mistakes
- Opening with a quotation or a statistic instead of your own point.
- Covering two ideas, which usually means the paragraph should be split.
- Repeating the thesis word for word.
Final Thoughts
Topic sentences are the skeleton of an essay: read them in order and you should have a summary of the argument. That makes them the quickest check of coherence and of the overall essay structure, and the starting point of every body paragraph.