The document discusses pragmatics, which includes the context and background of a conversation. Pragmatics are divided into presuppositions, topics, and conversational maxims. Presuppositions are implied assumptions in language. Topics refer to what a sentence is about. Conversational maxims like relevance, quality, quantity, and manner provide guidelines for effective communication. The document also discusses differences between languages and how languages evolve over time through processes like mutation, heredity, and isolation.