Yes, the word 'that' functions as an adjective, an adverb, a conjunction, a demonstrative pronoun, and a relative pronoun.A relative pronoun introduces a relative clause, a group of words with a subject and a verb that 'relates' information about its antecedent. (This description includes a relative clause introduced by the relative pronoun 'that'.)The relative pronouns are: who, whom, whose, which, and that.More examples:This is the movie that I like.That is the movie that Marie likes.Note: The demonstrative pronouns 'this' and 'that' are the subject of both example sentences.