Each paragraph should focus on one main idea.

Knowing how to write a strong paragraph is the first step in creating a successful paper. A paragraph is a collection of sentences related to a single point or idea. The structure of a basic paragraph includes a topic sentence and supporting sentences that help develop that idea. It’s also important for paragraphs to be well organized and coherent so that the reader can easily follow your writing.

Focus on One Idea

The general rule when writing paragraphs is to focus on one idea per paragraph. This helps create unity within the paragraph, so each sentence within the paragraph relates to only one point. If you find yourself transitioning to a new idea, start a new paragraph. You can test for unity by identifying the main point of your paragraph, then checking to see whether all of your sentences relate to that one point. If you have multiple ideas in that paragraph, split it into multiple paragraphs.

Begin with a Topic Sentence

The topic sentence expresses the main idea of your paragraph and summarizes the information in that paragraph. Usually, the topic sentence is the first sentence of the paragraph, though it can appear elsewhere. The topic sentence controls the paragraph, meaning that all the ideas expressed in the paragraph must relate to the topic sentence. For example, if your topic sentence is about the growing number of e-books available in public libraries, the rest of the sentences in that paragraph must relate to that idea. One way to write a good topic sentence is to think about the main points you want to make in your paper. Each of those points should become a topic sentence, with the rest of the sentences offering discussion and detail.

Create Supporting Sentences

Supporting sentences reinforce the main idea expressed in the paragraph's topic sentence. Supporting sentences provide examples, discuss the main idea, or offer more details for the reader to consider. Supporting sentences should be organized in a way that is coherent and logical so that the reader can follow your writing. This means using a consistent verb tense and point of view. Another way to achieve cohesion is to create bridges between sentences, for example, by using the words “first,” “second” and “third” to list points in the order of importance. Another way to create cohesion is to write a concluding sentence as the last sentence of your paragraph. This concluding sentence should summarize your main idea and reinforce your topic sentence.

Check for Completeness

A complete, or well-developed, paragraph presents an idea in the topic sentence, then offers enough detail, examples, facts or discussion for the reader to understand that main idea. Typically, a complete paragraph has at least five sentences, including the topic sentence, three or more supporting sentences, and a concluding sentence. Though some paragraphs may be shorter, a paragraph of only two or three sentences may not include enough information to adequately develop the main idea.