The document discusses the concept of "topic-stress", which is a rule for structuring sentences. According to this rule, the topic of the sentence should come near the beginning, while the stress or emphasis should come near the end. Properly applying topic-stress can influence the overall impression or tone conveyed by a sentence. A series of examples are provided to illustrate how moving elements like positive or negative phrases to different parts of the sentence changes the meaning or tone. The document suggests topic-stress is a useful concept for understanding how to structure information in a sentence.