Predicate logic is different from propositional logic because

predicate logic does not follow the rules of propositional logic.

predicate logic is used for inductive proofs, whereas propositional logic is used for deductive proofs.

predicate logic is used for deductive proofs, whereas propositional logic is used for inductive proofs:

predicate logic only analyzes whole atomic statements, whereas propositional logic analyzes the subjects and predicates of atomic statements.

predicate logic analyzes the subjects and predicates of atomic statements, whereas propositional logic only analyzes whole atomic statements.