What’s the difference between a predicate noun and a predicate adjective?

Predicate nouns are also known as predicate nominatives. They are a type of subject complement—they follow linking verbs to identify or redefine the subject. They are always nouns or pronouns (e.g., “Winston is a plumber”).

Predicate adjectives are also subject complements, but they are adjectives or adjective phrases that describe the subject (e.g., “Winston is funny”).