Building Paragraphs
A sentence carries one complete thought. A paragraph carries one developed thought — a main point supported by evidence, example, and explanation. Learning to build a paragraph is learning to think on the page: to take an idea, commit to it, and develop it until a reader understands it as fully as you do.
The structure of a paragraph
A well-built paragraph has three parts: a topic sentence, supporting sentences, and a concluding sentence.
The topic sentence states the paragraph's main point. It comes first, usually, and it makes a specific, arguable claim — not just a fact, but a point that the rest of the paragraph will support. Learning a new language requires daily practice. That is a topic sentence: it makes a claim, and the reader now expects the paragraph to support it.
The supporting sentences are the body of the paragraph. They provide evidence, examples, reasons, and explanation that develop the topic sentence. Each supporting sentence should connect to the topic sentence — if you find yourself writing a sentence that has nothing to do with the main point, it does not belong in this paragraph.
The concluding sentence wraps the paragraph up. It does not just repeat the topic sentence word-for-word — it restates the main point in light of what the supporting sentences established, or it points toward what comes next.
Unity — one point per paragraph
A paragraph should be about one thing. If you find yourself covering two separate points in one paragraph, split it into two paragraphs. This is called unity: every sentence in the paragraph serves the same central point.
The test for unity: read each sentence and ask, does this support the topic sentence? If yes, it belongs. If it is about something else — even something related — it belongs in its own paragraph.
Coherence — sentences that flow
A paragraph can have unity — every sentence on the right topic — but still read as a disconnected list. Coherence is what makes sentences flow naturally from one to the next, so the paragraph reads as a connected whole rather than separate pieces.
Coherence comes from two main tools. First, transitions: words and phrases that show how one sentence relates to the next. First, Second, Third, Additionally, However, Therefore, For example, In contrast, As a result. These words signal the relationship between ideas — that one adds to another, contrasts with it, provides an example, or follows from it.
Second, repetition and reference: using pronouns or synonyms to refer back to a word from the previous sentence creates a thread the reader can follow. The dog was hungry. It had not eaten since morning. The pronoun it refers back to dog, connecting the two sentences.
How long should a paragraph be?
A paragraph should be as long as it needs to be — no longer, no shorter. In practice, for most expository writing (writing that explains or argues), this means three to eight sentences. Fewer than three and the point is usually underdeveloped. More than ten and the paragraph usually covers too much ground and should be split.
A one-sentence paragraph is not wrong — it can be very effective for emphasis. But it should be rare and deliberate, not a sign that you could not think of anything to support your point.
What this unlocks
You can now build the block that all extended writing is made of. A paragraph is what allows you to take a single idea and give it the space it deserves — to develop it, support it, and make it convincing. The final chapter in this course assembles paragraphs into complete pieces of writing: how to plan, draft, and revise a composition that communicates clearly from beginning to end.