Which category of pronouns emphasize a noun but do not change its meaning?

Intensive pronouns are designed specifically to add emphasis to a noun already present in the sentence. They mirror the structure of reflexive pronouns but serve a different purpose. For example, in the sentence "The principal himself approved the project," the intensive pronoun "himself" emphasizes that it was the principal who took action, but it does not alter the fundamental meaning of the sentence. It simply stresses the importance of the noun it modifies.

Reflexive pronouns, while they can emphasize a noun, do so in a way that is inherently tied to the action of the verb and usually indicates that the subject and object of the verb are the same person or thing. Indefinite pronouns refer to nonspecific persons or things, and subject pronouns identify the subject of a sentence. Neither of these categories serves the purpose of providing emphasis without altering meaning like intensive pronouns do.

Therefore, the choice that best fits the definition of pronouns that emphasize a noun without changing its meaning is indeed intensive pronouns.