Pronouns and Determiners - Non-Assertive Indefinite Pronouns and Determiners

an unspecified amount or selection of something, regardless of its quantity or magnitude

used for referring to a person when who that person is does not matter

used to refer to a person, regardless of their identity, characteristics or specific attributes

used for referring to a thing when it is not important what that thing is

one or some of a thing or number of things, however large or small