You will learn
- Define a topic sentence.
- Write one that states the main idea.
- Place it at the start.
- Check that details match it.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- A topic sentence states the main idea.
- It usually comes first.
- It should not be too big or too small.
- Every detail must match it.
Words to know
a group of sentences about one idea
a sentence that states the main idea
what the paragraph is about
a sentence that gives a detail
1. Discover: Our school library
Our school library is a quiet place full of useful books. It has shelves of stories and facts about animals, places and people. Children can read at tables or borrow books for home. The librarian helps us find the right book.
Think: Which sentence tells the main idea?
2. Understand: The sentence that leads
Idea 1: What it is
A paragraph is about one idea. The topic sentence states that main idea.
Idea 2: Where it goes
Put it first so readers know what is coming. The other supporting sentences add details.
Idea 3: Make it right
It must not be too small (The library has books.) or too big (Libraries are important.).
3. Worked examples
Example 1 (I show you): Find
Find the topic sentence.
- First sentence.
Answer: Our school library is a quiet place full of useful books.
Example 2 (We do it together): Detail
Name a supporting sentence.
- A detail.
Answer: Children can read at tables or borrow books for home.
Example 3 (You try): Match
Does the librarian help sentence match?
Show the steps and answer
- Does it support?
Answer: yes
Did you know?
Newspaper writers often put the most important sentence first.
Why this matters
A clear topic sentence keeps your paragraph focused.
4. Explore: Topic sentence workshop
Write topic sentences.
- Choose a topic.
- Write a topic sentence.
- Add three details.
- Check they match.
Think about it: what did you notice?
You can write a topic sentence.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- My topic is ___.
- My topic sentence is ___.
- One detail is ___.
- Another detail is ___.
Guided practice
Question 1. A group of sentences about one idea is a ___.
paragraph
Question 2. A sentence stating the main idea is a ___ sentence.
topic
Question 3. What the paragraph is about is the ___ idea.
main
Independent practice
Level 1: Start
- A group of sentences about one idea is a ___.
- A sentence stating the main idea is a ___ sentence.
- What the paragraph is about is the ___ idea.
- A sentence giving a detail is a ___ sentence.
- Our school library is full of useful ___.
Level 2: Grow
- Write a topic sentence about your pet.
- Is Libraries are important too big or small?
- Name a library detail.
Level 3: Stretch
- Is the topic sentence usually first?
- Must details match?
- Is one idea per paragraph best?
Answers are in the answer key below. Try first, then check.
6. Apply: English in everyday life
Write a paragraph with a topic sentence and three details.
Show a sample answer
a paragraph
Another one. Write two paragraphs, each with a clear topic sentence.
Show a sample answer
a completed task
7. Common mistakes
Fix: Slow down and check your work.
Fix: Study the example first, then try.
8. Lesson summary and revision card
- I can define a topic sentence.
- I can write one that states the main idea.
- I can place it at the start.
- I can check that details match it.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- A topic sentence states the main idea.
- It usually comes first.
- It should not be too big or too small.
- Every detail must match it.
11. Next lesson
Next lesson: Supporting details. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- What is a topic sentence? [1 mark]
- Where does it usually go? [1 mark]
- Write a topic sentence about your school. [2 marks]
- Give two supporting sentences for it. [2 marks]
- Explain how to write a good topic sentence. [3 marks]
Total: 9 marks.
Marking guide and model answers
- a sentence that states the main idea [1]
- at the start of the paragraph [1]
- states a main idea [1]; clear and focused [1]
- detail [1]; detail [1]
- choose one main idea [1]; state it clearly, not too big or small [1]; make sure details match [1]
Score guide: 8 to 9 = secure. 6 to 7 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- A group of sentences about one idea is a ___.
- A sentence stating the main idea is a ___ sentence.
- What the paragraph is about is the ___ idea.
- A sentence giving a detail is a ___ sentence.
- Our school library is full of useful ___.
- Write a topic sentence about your pet.
- Is Libraries are important too big or small?
- Name a library detail.
- Is the topic sentence usually first?
- Must details match?
Homework
Write two paragraphs, each with a clear topic sentence.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. A group of sentences about one idea is a ___. | paragraph | 1 |
| 2. A sentence stating the main idea is a ___ sentence. | topic | 1 |
| 3. What the paragraph is about is the ___ idea. | main | 1 |
| 4. A sentence giving a detail is a ___ sentence. | supporting | 1 |
| 5. Our school library is full of useful ___. | books | 1 |
| 6. Write a topic sentence about your pet. | My pet is friendly and funny. | 1 |
| 7. Is Libraries are important too big or small? | too big | 1 |
| 8. Name a library detail. | tables to read at | 1 |
| 9. Is the topic sentence usually first? | yes | 1 |
| 10. Must details match? | yes | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 paragraph; 2 topic; 3 main; 4 supporting; 5 books. Level 2: 1 My pet is friendly and funny.; 2 too big; 3 tables to read at. Level 3: 1 yes; 2 yes; 3 yes.
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Define a topic sentence | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Write one that states the main idea | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Place it at the start | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Check that details match it | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: Rushing without checking. Slow down and check your work.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Re-read the examples slowly and use the sentence frames.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child practises a key Grade 3 English skill with clear examples and a quiz. You do not need to be an expert to help.
- Listen while your child explains the idea.
- Ask for one new example.
- Praise effort and careful work.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: define a topic sentence; write one that states the main idea; place it at the start; check that details match it.
Prerequisite knowledge. Grade 2 paragraph writing.
Materials. Chart paper or board, pencils, picture or word cards, a reading book if available. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Write the key words and examples on the board or on cards before the lesson.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Introduce the idea with the opening example.
Explanation (10 min). Teach the key words.
Guided activity (10 min). Practise together.
Independent activity (10 min). Check understanding with the quiz.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. What is the key idea? Can I give my own example?
Teacher explanation notes. Move from the spoken word to pictures and then to print. Read aloud often, point to the words, and let learners hear and say before they read and write.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use the sentence frames and work with a partner. Extension. Create a harder example of your own.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. Rushing without checking. Slow down and check your work.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 9-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Re-read the examples slowly and use the sentence frames. Enrichment. Make up your own example and teach it to someone at home. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Common Core State Standards for English Language Arts, Cambridge Primary and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Official standards for this topic area. Common Core State Standards for English Language Arts (official site): Grade 3 » Writing; Grade 3 » Language. These pages list the standards that cover this topic area; read them alongside the lesson.
Research used to shape this lesson. Common Core W.3.2a (introduce a topic and group related information together; include illustrations when useful to aid comprehension) and W.3.2b; Cambridge Primary English Stage 3 (writing). These sources informed the lesson.