Linking verbs show existence but no action. In some sentences, a linking verb links the subject to a noun that renames the subject. We call that renaming word a predicate nominative. Look at these examples:
Peter is a boy. The noun boy renames Peter.
My grandfather was a doctor. The noun doctor renames grandfather.
Julie is his daughter. The noun daughter renames Julie.
A noun that follows a linking verb and renames the subject of the sentence is called a predicate nominative.
▶It’s your turn. Find the predicate nominative in this sentence: Mr. Smith is my teacher. Did you figure it out? Good for you!