The document discusses the constituent functions of noun phrases and sentences. It describes noun phrases as having three main functions: subject of a deep structure sentence, object of a verb phrase, and subject of a surface structure sentence. It provides examples to illustrate deep structure subjects and objects, and how subjects and objects can differ between deep and surface structures. The document also discusses other syntactic functions that embedded sentences can have, such as relative clauses, noun phrase complements, and verb phrase complements.