Thread:Ahsan1444/@comment-43604755-20190909173317/@comment-37875052-20190910171640

Staff is English word. And what was your mistake. You either read the article in hurry or only in half.

Staff as in your faculty does not need a plural as it is a collective noun referring to the group of teachers already.

Staff as in fighting weapon mostly made of wood is a singular word whose plural is staves.