An antecedent is the noun or pronoun that a pronoun replaces.The noun or pronoun either precedes the pronoun in the same sentence, a previous sentence, or is known to the speaker and those spoken to.For example:When George got to 19th Street, he got off the train."George" is the antecedent of the pronoun "he."Students in on-line classes have to keep up with their assignments. The word "students" is the antecedent of the word "their."