代词和限定词 - 断言不定代词和限定词

used to denote a certain, but unspecified, portion or selection of things or people

一些, 某些

a person who is not mentioned by name

某人, 一个人

a person whose identity is not specified or known

有人, 一个人

used to mention a thing that is not known or named

某物, 东西

used to express an unspecified amount or number of something

一些, 若干

used to refer to an unspecified selection within a group or category

某些, 特定的