A paragraph should have a strong topic sentence, and then other sentences which give details and facts to support it. Read each sentence, then decide whether it seems like a topic sentence or a supporting sentence.
Topic Sentence
Supporting Sentence
Building a birdhouse can be lots of fun.
:: Friends can work together on planning and building the birdhouse.
When you paint it you can go wild with the colors.
:: Our PE teacher is really tough sometimes.
She blows the whistle really loudly.
:: We have to run lots and lots of laps.
:: Once we had to run in the rain!