A paragraph is a group of sentences about one main idea. A good paragraph tells the reader what the idea is, supports it with details or examples, and finishes neatly. In most school and exam writing, a paragraph is 100–150 words (5–8 sentences), though short paragraphs are normal in emails and online writing.

The three-part paragraph structure

PartJobTip
Topic sentenceStates the main idea of the paragraphUsually the first sentence. Make it specific enough to be developed.
Supporting sentences (3–5)Explain, give reasons, examples, facts or detailsEvery sentence must connect to the topic sentence.
Concluding sentenceSums up or links to the next ideaRestate the idea in new words — don't add a new point.
Think of a burger: the topic sentence and concluding sentence are the bread; the supporting sentences are the filling. Without bread it falls apart; without filling there's nothing to eat.

Writing a strong topic sentence

Too generalToo narrowJust right
Exercise is good.I walked 4,000 steps yesterday.A short daily walk improves both physical and mental health.
Mobile phones are everywhere.My phone has a 6.5-inch screen.Mobile phones have changed the way students study.

A good topic sentence has a topic (a short daily walk) and a controlling idea — what you'll say about it (improves physical and mental health).

Four types of paragraph (with examples)

1. Descriptive paragraph — paints a picture

My grandmother's kitchen was the warmest room in the house. Brass pots hung in a neat row above the stove, catching the morning light. The air always smelled of cardamom and fresh rotis, and a small radio played old film songs in the corner. On the windowsill, a tulsi plant grew in a cracked clay pot she refused to replace. Even today, the smell of cardamom takes me straight back to that small, bright room.

Uses: sense details (sight, smell, sound), specific nouns, adjectives.

2. Narrative paragraph — tells a story

The day I missed the school bus taught me to plan ahead. I had stayed up late finishing a project, so I slept through my alarm. When I reached the stop, the bus was already turning the corner. I ran after it, waving my arms, but the driver didn't see me. In the end, my father had to leave work to drive me, and I arrived just as the exam began. Since then, I have never left an assignment until the night before.

Uses: past tenses, time order (then, when, in the end), a lesson or result.

3. Expository paragraph — explains or informs

Rainwater harvesting is a simple way to save water at home. Rain that falls on a roof is collected through pipes and stored in a tank or directed into the ground. The stored water can be used for gardening, washing or, after filtering, even drinking. In cities, it also reduces flooding because less water runs into overloaded drains. For these reasons, many local governments now require new buildings to include a harvesting system.

Uses: facts, clear steps, neutral tone, often the passive voice.

4. Persuasive (argumentative) paragraph — convinces

Schools should start an hour later in the morning. Teenagers' sleep patterns naturally shift later, so early classes leave many students tired and unable to concentrate. A later start would give them more rest, which is linked to better attention, mood and exam results. Some argue that a later start would disrupt parents' work schedules; however, the benefit to students' learning is more important. A small change in timetables could make a large difference to education.

Uses: a clear opinion, reasons, a counter-argument, a strong final line. This is the paragraph type used in essays — see essay structure.

Unity and coherence: what makes a paragraph "flow"

  • Unity: every sentence supports the topic sentence. If a sentence talks about something else, move it or delete it.
  • Coherence: sentences follow a logical order — time order, order of importance, or general → specific.
  • Linking words: show the relationship between sentences.
RelationshipLinking words
Addingalso, in addition, furthermore, besides
Time / sequencefirst, then, after that, finally, meanwhile
Examplefor example, for instance, such as
Contrasthowever, but, on the other hand, although
Resultso, therefore, as a result, consequently
Concludingin short, overall, for these reasons

Common paragraph mistakes

MistakeFix
No topic sentence — the reader has to guess the pointStart with a clear one-sentence summary of the idea.
Two main ideas in one paragraphSplit them into two paragraphs.
Every sentence starts with "I" or "Also"Vary sentence openings and linking words.
A list of facts with no explanationAfter each fact, say why it matters.
Very long sentences joined with commasUse full stops — see comma splices.

Paragraph writing in 5 steps (for exams)

  1. Read the topic and decide the type: describe, narrate, explain or persuade.
  2. Brainstorm 3–4 supporting points in 1 minute.
  3. Write the topic sentence with a clear controlling idea.
  4. Develop each point in one or two sentences, with an example.
  5. Conclude and check word count, spelling and punctuation. Use our word counter to practise.

Which sentence does not belong?

Topic sentence: Reading every day has many benefits for students.

  1. It builds vocabulary without the need to memorise lists.
  2. It improves concentration and patience.
  3. My favourite author writes detective novels.
  4. It shows students how good sentences are structured.
Show answer

c — it's about the writer's taste, not a benefit of reading. It breaks the paragraph's unity.

Frequently asked questions

What are the three parts of a paragraph?

A topic sentence that states the main idea, supporting sentences that explain it with reasons, details or examples, and a concluding sentence that sums it up.

How long should a paragraph be?

In school and exam writing, usually 100–150 words or about 5–8 sentences. Emails and online articles often use shorter paragraphs.

What are the types of paragraphs?

The four main types are descriptive (describes), narrative (tells a story), expository (explains or informs) and persuasive (argues an opinion).

What is a topic sentence?

It is the sentence, usually the first, that states the main idea of the paragraph and the point you will make about it.

How do I make a paragraph flow?

Keep every sentence focused on one idea, arrange sentences in a logical order and use linking words such as however, for example and as a result.

Related notes:
Essay Writing StructurePunctuation RulesReport WritingHow to Write an EssayWord Counter