Listening and Speaking 115/120: Choose a topic to free write about

Topic sentence
One sentence which states your idea, point, or opinion. This sentence should use a strong verb and make a bold statement.

For example: Students require more recreational time in order to better focus on lessons in class.

NOTE: Notice the strong verb 'require' which is a call to action. A weaker form of this sentence might be: I think students probably need more recreational time ... This weaker form is inappropriate for a topic sentence.
Supporting sentences
Supporting sentences (notice the plural) provide explanations and support for the topic sentence (main idea) of your paragraph.

For example: In fact, studies have shown that students who enjoy a recess of more than 45 minutes consistently score better on tests immediately following the recess period. Clinical analysis further suggests that physical exercise greatly improves the ability to focus on academic materials.

NOTE: Supporting sentences provide the evidence for your topic sentence. Supporting sentences that include facts, statistics and logical reasoning are much more convincing that simple statements of opinion.
Concluding sentence
The concluding sentence restates the main idea (found in your topic sentence) and reinforces the point or opinion.

For example: Longer periods of recess are clearly required to allow students the best possible chances of success in their studies.

NOTE: Concluding sentences repeat the main idea of your paragraph in different words.
Transitional sentence
The transitional sentence prepares the reader for the following paragraph.

For example: Clearly, physical exercise is just one of the necessary ingredients for improving student scores on standardized tests.

NOTE: Transitional sentences should help readers logically understand the connection between your current main idea, point or opinion and the main idea of your next paragraph. In this instance, the phrase 'just one of the necessary ingredients ...' prepares the reader for the next paragraph which will discuss another necessary ingredient for success.