Faulty pronoun reference will confuse readers. A pronoun must clearly refer to an antecedent or readers will become confused. There are two kinds of pronoun reference errors.

1. Vague Reference. Sometimes a writer will forget to put the antecedent on paper, thus creating an unclear message. The most common pronoun that causes this error is they.
Error: When my father was a child, they thought children should be seen and not heard.
Solution: When my father was a child, adults thought children should be seen and not heard.

2. Ambiguous Reference. Sometimes a pronoun could refer to two antecedents. This is always an error since a pronoun should refer to only one antecedent. Try rewriting the sentence.
Error: Anita told her sister she thought she looked better in red.
Solution: Anita said her sister looked better in red.