An antecedent is a word which a pronoun refers to.

Examples:

• The day of the graduation came. It was a memorable one.

The word day is the antecedent of it.

• Kyla got a puppy. It was a gift from her grandparents.

The word puppy is the antecedent of it.

• Kyla was happy that she received a medal.

The word Kyla is the antecedent of she.

• Her grandparents were around. They came from the province.

The word grandparents is the antecedent of they.

• Her teachers attended the party. They were very happy for her.

The word teachers is the antecedent of they.

The words it, she, and they are pronouns. They refer to day, puppy, Kyla, grandparents, and teachers. The words they refer to are their antecedents.