Dissect well-written paragraphs with students. Classify sentences in the paragraphs as "topic" or "supporting" sentences and explain how each functions.
Show well-written paragraphs to students. Have them find and highlight topic sentences. Discuss why each would be considered the topic sentence.
Present a selection of paragraphs to students, some with well-written and some with poor or no topic sentences. Have students sort paragraphs according to whether or not each has a good topic sentence.
Give students a selection of sentences from a paragraph in random order and have them choose which is likely to be the topic sentence. Repeat with other paragraphs until students can reliably choose the topic sentences from the paragraphs presented and explain their choices.
Summarize the concept of a topic sentence as a sentence that introduces the topic, engages the reader, and ties the supporting sentences together. Remind students that topic sentences should introduce the subject and be related in some way to each of the supporting sentences.
Provide students with supporting sentences that can be used to create a paragraph and challenge them to generate a matching topic sentence. Be sure the sentence created introduces the subject effectively and connects to all of the supporting ideas.
Have students brainstorm details and supporting ideas about a chosen topic. Instruct them to then use these ideas to craft a topic sentence that effectively introduces the subject and is related to all of the supporting details to be included in the paragraph. Have the students write the paragraph. Practice until students automatically begin with good topic sentences when writing paragraphs.