"Frank Zappa, who was one of the most creative artists in Rock 'n Roll, came from California." In this sentence, who was one of the most creative artists in Rock 'n Roll is an example of a non-defining relative clause and who is the relative pronoun. Take this relative clauses quiz to check your understanding of the use of relative pronouns. For explanations visit the following pages:

Introduction to Relative Clauses
Defining Relative Clauses
Non-Defining Relative Clauses