Topic Sentences

• 3rd grade
• 4th grade
• CCSS W.3.2a
• CCSS W.3.1a
• CCSS W.4.2a

A topic sentence tells the reader what a paragraph is about. It's usually the first sentence, and it states the main idea that every other sentence supports. A strong topic sentence is not too broad, not too narrow, and makes the reader want to keep going.

What makes a strong topic sentence?

A topic sentence has two parts: the topic (what you're writing about) and the controlling idea (what you'll say about it). In "Penguins are built for life in the cold," the topic is penguins and the controlling idea is that they're built for cold. Every detail in the paragraph should prove that.

Too broad: "Animals are interesting." That could be a whole book. Too narrow: "Penguins have black feathers." That's just one detail. Just right: "Penguins are built for life in the cold." It covers the whole paragraph and nothing more.

3rd graders introduce a topic and group information (W.3.2a) and state an opinion with a structure (W.3.1a); 4th graders introduce topics clearly and organize paragraphs (W.4.2a). Topic sentences are what readers look for when they find the main idea.

Too broad, too narrow, just right

The same topic, three ways.

Test it: could you write three or four detail sentences that prove it? If you'd need a whole book, it's too broad. If there's nothing more to say, it's too narrow.

Ways to start with a hook

Topic sentences can be plain or catchy. These are all just right.

1. Statement: Owls are excellent night hunters.
2. Question: Have you ever wondered how owls hunt in the dark?
3. Surprising fact: An owl can turn its head almost all the way around.
4. Opinion: I think owls are the most amazing birds of the night.
5. Sound or image: Swoosh! An owl swoops silently out of the dark.
6. Too broad: Birds are cool.
7. Too narrow: Owls have two eyes.
8. Announcement: This paragraph is about owls. (avoid)
9. Fix: Owls have amazing eyes that help them see at night.
10. Check: do the details all fit?

Avoid "This paragraph is about..." or "I am going to tell you...". Just state the idea.

How to teach topic sentences

Five short steps, about 10 minutes each.

1. Find them. Underline topic sentences in nonfiction books.
2. Name both parts. Topic + controlling idea.
3. Sort them. Too broad, too narrow, just right.
4. Write from details. Given three details, write the topic sentence.
5. Add a hook. Try a question or surprising fact.

Common mistakes and how to fix them

Practice: topic sentences quiz

10 questions. Your child can tap the speaker to hear a question read aloud. The first try on each question counts toward the score.

1. 1.What does a topic sentence do?

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   tells what the paragraph is about ends the paragraph gives one small detail
   Show answer

   Tells what the paragraph is about.

2. 2.Which topic sentence is just right?

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   Owls are excellent night hunters. Birds are cool. Owls have two eyes.
   Show answer

   Owls are excellent night hunters.

3. 3.Sports are fun. This topic sentence is...

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   too broad too narrow
   Show answer

   too broad.

4. 4.Pizza has cheese. This topic sentence is...

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   too narrow too broad
   Show answer

   too narrow.

5. 5.Where does the topic sentence usually go?

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   at the start of the paragraph in the middle
   Show answer

   At the start of the paragraph.

6. 6.Which should you avoid?

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   This paragraph is about dogs. Dogs make loyal pets.
   Show answer

   This paragraph is about dogs.

7. 7.Tap the topic word.

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   Recess helps kids learn better.

   Show answer

   Recess.

8. 8.Details: loyal, love to play, can learn tricks. Best topic sentence?

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   Dogs make great pets. Dogs bark.
   Show answer

   Dogs make great pets.

9. 9.Which is a question hook?

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   Have you ever wondered how owls see at night? Owls see at night.
   Show answer

   Have you ever wondered how owls see at night?

10. 10.What are the two parts of a topic sentence?

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    topic and controlling idea title and author
    Show answer

    Topic and controlling idea.

Topic Sentences worksheet (free PDF)

Topic Sentences Worksheet, 3rd–4th grade

Sort topic sentences as broad, narrow or just right, write topic sentences for details, and add a hook. Prints on US Letter paper, with an answer key.

Download the PDF

Try it at home

• Book hunt: underline topic sentences in a nonfiction book.
• Goldilocks test: too big, too small, just right?
• Details first: list three, then write the topic sentence.
• Hook practice: start with a question.
• Headlines: turn a headline into a topic sentence.

What comes next

Next: transition words. Earlier: descriptive writing and writing a paragraph. Related reading: main idea.

Last reviewed: November 11, 2026

Questions parents ask