An antecedent is a thing that does before. So ante, means before and cedent is like a going -ee thing

Whenever you use a pronoun you are referring back to something else the thing that went before the antecedent, the thing that has come previously so you want to make sure that these things match up

Example

• Jillian rode her bike to the grocery store

• she bought some garlic and a spoon

• The monkey threw the ball, but it had the crummy aim