Some examples of relative pronouns in action (introducing adjective clauses) would be the following:
The crowd cheered the runner who broke last year’s record.
Her favorite homemade cookies, which have been awarded many prizes, have the perfect balance of chocolate and peanut butter.
Shandra, whose essay won first place, will attend our local college in the fall.
The class president will be Jerome, whom we met last summer at camp.
I reached for the bowl that was on the top shelf.