Pragmatics deals with language use and context. Presuppositions are implicit assumptions about information speakers expect hearers to know, like background facts. For example, asking "Did you know John and Mary split up?" presupposes the hearer knows they were a couple. Implicatures go beyond literal meaning to infer intention. For example, saying "I'm busy" in response to "Are you coming to the party?" implies the speaker won't attend. Entailments are inferences that don't depend on context, like the statement "Jane no longer writes fiction" presuming she once did. Presuppositions are crucial to understanding meaning beyond words in conversations.