Question

The boy who stole your pen has been punished is which pronoun?

Answer 1

Since ‘who’ has been applied here, it’s a relative pronoun.

Answer 2

In the sentence,"The boy who stole your pen has been punished", the pronoun is "who".

This is a relative pronoun.

Relative pronouns are used to join two sentences by establishing a relation between two nouns.

This is a complex sentence as a relative pronoun has been used in this sentence.