A pronoun takes the place of one or more nouns or other pronouns.
The word that a pronoun stands for is called the antecedent.
1. Leading Ryan to the display case, Katie said, “These are the watches I described to you earlier.”
2. People write to that columnist because he offers easy solutions.
3. Jenna and Amy went to visit their grandmother in Memphis.
Pronouns can be the subject of a sentence or the object of a sentence. When a pronoun is a subject, it replaces the primary noun of the sentence and is the noun performing the action. When a pronoun is the object of a sentence it is the noun receiving the action.
Subject: He likes apple pie. Object: John likes it.