Building a paragraph
Most writing, in school and after it, is built from one unit: a paragraph that makes a point and backs it up. The same four parts — topic sentence, supporting details, explanation, closing sentence — work in a story, a persuasive piece and a research report. What changes is what counts as a detail.
Why does a paragraph need a shape?
Because a reader can only follow one point at a time. A paragraph that states its point first tells the reader what every sentence after it is for. One that does not leaves them guessing, and most readers either guess wrong or stop reading.
The shape also keeps the writer honest. If you cannot write the topic sentence, you do not yet know what the paragraph is about. If a detail has nothing after it, you have listed it, not shown why it matters.
And it grows. A report, a speech or an essay is several good paragraphs in a sensible order. Learn to build one well and you can build the rest.
Where it turns up
- A news story — the first sentence gives the most important point, and the details follow in order of how much they matter, so a reader who stops early still gets the news
- A product review — the reviews people find most helpful give a verdict, then specifics: the zipper broke after two weeks, the battery lasted six hours
- A science lab report — the conclusion states what the results show, gives the measurements that show it, and explains what they mean
- A job application — a cover letter paragraph names something you can do, gives one real example, and says why it matters to that employer
- 1. The words, first
- 2. The four parts
- 3. The explanation is the part that counts
- 4. One shape, three jobs
- 5. What costs marks
The words, first
The idea: Explanation is the part that turns details into proof.
| Word | What it means |
|---|---|
| Paragraph | A group of sentences about one main point. |
| Topic sentence | The sentence that states the point, usually first. |
| Supporting detail | Anything that backs up the point: a fact, an example, a reason, a quotation — or, in a story, an action or a sensory detail. |
| Explanation | What a detail means: how it proves the point. Also called elaboration. |
| Closing sentence | The last sentence. It brings the point home or, in a story, leads into what comes next. |
| Transition | A word or phrase that links one idea to the next: for example, also, however, then. |
| Claim | In persuasive writing, the opinion you want the reader to accept. |
| Evidence | Facts, numbers or examples that support a reason. |
| Source | Where a fact came from: a book, a website, an interview. |
The four parts
The idea: Point, detail, explanation, close. Each part answers a question the reader would otherwise have to ask.
Moose are built for Alberta winters. Their legs are so long that they can walk through snow deep enough to stop a deer. That matters because deep snow is what traps shorter animals, so a moose can keep moving to find food when others cannot. Their thick coat is made of hollow hairs, and the air inside each hair holds in body heat the way the stuffing in a winter jacket does. Even their diet fits the season: when plants are buried, moose live on the twigs and bark of willow and aspen. From their legs to their lunch, moose are made for the cold.
| Part | The reader's question | In the moose paragraph |
|---|---|---|
| Topic sentence | What is this about? | Moose are built for winter. |
| Details | How do you know? | Long legs, hollow hairs, a winter diet. |
| Explanations | So what? | Deep snow traps other animals; trapped air holds heat. |
| Closing sentence | What does it add up to? | Every part of a moose suits the cold. |
Transitions hold it together: That matters because links a detail to its explanation, and Even adds one more detail on the same point.
The explanation is the part that counts
The idea: A detail on its own is only a list. Ask “so what?” after every detail and write the answer down — that answer is the explanation.
Our town should build an outdoor rink in Riverside Park. Lots of kids like skating. The nearest rink is far away. Skating is good exercise. That is why we need a rink.
Every sentence is on topic, and it still proves nothing. Ask “so what?” after each detail. The nearest rink is far away — so kids who cannot get a ride do not skate at all. Skating is good exercise — and in the months when it is dark by five, it is one of the few ways to be active outside.
Our town should build an outdoor rink in Riverside Park. The nearest rink is across the highway, so kids who cannot get a ride do not skate at all. A rink within walking distance would change that for every family on the east side. It would also give kids a way to be active outside in the months when it is dark by five. Flooding the ice on cold nights is a small price for a place the whole neighbourhood can use.
The details barely changed. Each one now says why it matters, and the closing sentence adds something instead of repeating the first.
One shape, three jobs
The idea: The four parts stay. What counts as a detail changes: an action in a story, a reason with evidence in a persuasive paragraph, a fact from a source in research.
| Part | Story | Persuasive | Research |
|---|---|---|---|
| Topic sentence | The moment in focus | Your claim | The point your facts support |
| Details | Actions, dialogue, senses | Reasons, with evidence | Facts from sources |
| Explanation | Often left for the reader | Why the reason should convince | What the fact means |
| Closing sentence | Leads into the next moment | What should happen | What the facts add up to |
The rink paragraph is the persuasive version. Here are the other two.
The dressing room went quiet when Coach walked in with the lineup. Jonah stopped taping his stick halfway down the blade. Beside him, Eli bent over a skate lace that was already tied. Nobody looked at the paper in Coach's hand. Coach cleared his throat and started reading names.
The story paragraph. The first sentence sets the moment. The details are actions, and they do their own explaining: stopping halfway and fussing with a tied lace show nerves without naming them. The last sentence pushes the reader into the next paragraph.
A chinook can turn an Alberta winter day upside down. It is a warm, dry wind that blows down the eastern side of the Rocky Mountains. According to the weather atlas in our school library, it can raise the temperature in southern Alberta by more than 20 degrees in a few hours. That means a morning well below zero can turn into an afternoon warm enough to melt snow off the roofs. The wind is so dry that snow can vanish almost overnight, which is why chinooks are sometimes called “snow eaters.” In Calgary or Lethbridge, a winter day can end feeling like spring.
The research paragraph. Each fact is followed by what it means. The surprising number comes with its source: according to is the simplest way to give credit inside a sentence.
What costs marks
The idea: Each one is a part missing, or a part doing the wrong job.
- No topic sentence, or one that announces: “In this paragraph I will talk about moose.”
- Details with no explanation. Ask “so what?”
- Two points in one paragraph. If a detail does not support the topic sentence, it belongs somewhere else.
- A closing sentence that copies the first one.
- Research facts with no source, or someone else's sentence with a few words swapped.