Just as your paper needs a guiding thesis statement to unify your essay, each paragraph needs a topic sentence to unify each section. They not only help to keep each paragraph cohesive, but also help your reader maintain focus on your overall argument, claim, or narrative theme.
Most often (though not always) the topic sentence is in the beginning of the paragraph. A strong topic sentence works to maintain the controlling idea in each paragraph. Without it, the paragraph will not only fall apart, but the paper can also fall apart as well. Think about what you want each paragraph to communicate; this is the controlling idea that focuses each paragraph. Each paragraph will connect back and support the thesis.
Lack of cohesive paragraphs is one of the most common problems with student writing. Each paragraph should have only ONE topic. In a research paper, each paragraph will argue or support only ONE point. Study the paragraph structure in one of your essays; if the paragraphs have several different ideas going on, each of those separate ideas need their own paragraph. In research papers, they need their own support and research. In longer research papers you might take more than one paragraph to argue a point, such as giving support or research. In this case, it’s okay to omit the topic sentence from a paragraph that is continuing in a line of inquiry or argument, though it’s important to have a transitional sentence to lead the reader along with you.
Topic Sentence Example
Topic sentences often act like tiny thesis statements. Like a thesis statement, a topic sentence makes a claim of some sort. As the thesis statement is the unifying force in the essay, so the topic sentence must be the unifying force in the paragraph. Further, as is the case with the thesis statement, when the topic sentence makes a claim, the paragraph which follows must expand, describe, or prove it in some way. Topic sentences make a point and give reasons or examples to support it.
Consider the last paragraph about topic sentences, beginning with the topic sentence itself:
Topic sentences often act like tiny thesis statements.
This is my claim, or the point I will prove in the following paragraph. All the sentences that follow this topic sentence must relate to it in some way.
Like a thesis statement, a topic sentence makes a claim of some sort. As the thesis statement is the unifying force in the essay, so the topic sentence must be the unifying force in the paragraph.
These two sentences show how the reader can compare thesis statements and topic sentences: they both make a claim and they both provide a focus for the writing which follows.
Further, as is the case with the thesis statement, when the topic sentence makes a claim, the paragraph which follows must expand, describe, or prove it in some way.
Using the transitional word “further” to relate this sentence to those preceding it, I expand on my topic sentence by suggesting ways a topic sentence is related to the sentences that follow it.
Topic sentences make a point and give reasons or examples to support it.
Finally, I wrap up the paragraph by stating exactly how topic sentences act rather like tiny thesis statements.
(Example from U of Ottowa)
One Last Word
Paragraphs come in many shapes and sizes, but the guiding principle on paragraph structure should always come back to the topic sentence. When revising your essay, ask yourself, is all of the information in this paragraph directly relating to the topic sentence? If not, get it out. Focus, focus, focus. Your readers will thank you.