No, a pronoun can function is any place that a noun will function in a sentence.A noun or a pronoun can be the subject of a sentence or a clause, and as the object of a verb or a preposition.Examples:Jill made the cakes. She is a very good cook.The personal pronoun she is the subject of the second sentence.Jack is away to school. I miss him.The personal pronoun him is the direct object of the verb 'miss'.The puppies need their immunizations.The possessive adjective their describes the direct object noun 'immunizations'.You should be very proud of yourself.The personal pronoun you is the subject of the sentence.The reflexive pronoun yourself is the object of the preposition 'of'.