Pragmatics deals with language use and context. Presuppositions are implicit assumptions about knowledge that speakers assume hearers already have, like assuming someone knows people in an example. Implicature conveys additional meaning beyond what is said literally. Entailment belongs to semantics as it is not affected by context. Presuppositions are taken for granted assumptions triggered by sentences, like assuming someone once wrote fiction in the sentence "Jane no longer writes fiction." Understanding presuppositions and implicature is important for comprehending intended meaning.