When communicating in Chinese you may often make mistakes using Chinese grammar like:

False:

    你等谁人？

    Nǐ děnɡ shuí rén

True:

    你等谁？

    Nǐ děnɡ shuí?

“谁”是用来咨询人的，可以单独做宾语。“人”多余。

谁 is an interrogative pronoun referring to a person. It can act as an object indepently, so 人 is redundant.