Definitions
(after a verb or adjective) one who (is) ...
(after a noun) person involved in ...
-er
-ist
(used after a number or 後|后[hou4] or 前[qian2] to refer to sth mentioned previously)
(used after a term, to mark a pause before defining the term)
(old) (used at the end of a command)
(old) this