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