Is his a subject pronoun or possessive pronoun?

The pronoun 'his' is a possessive pronoun, which functions as a subject of an object in a sentence; and a possessive adjective, which describes a subject or an object noun in a sentence.

The possessive pronoun 'his' takes the place of a noun that belongs to a male.

Examples:

My brother lives on this street. His is the house on the corner. (subject)

My brother lives on this street. The house on the corners is his. (object)

The possessive adjective 'his' is placed before a noun to describe the noun as belonging to a male.

Examples:

John took his mother to the doctor. (object)

His mother took John to lunch. (subject)