请问except,except for,except that三者之间的区别

Except 含有“除…之外”或“除了”的意思时， 通常用作介词而不是连词。人称代词用于except 之后时通常用宾格：
No one except me knew it.
除我之外没人知道它；
Every member of the original cast was signed except her.
除她之外的原班演员都是签约雇佣的
except for
adv.
除...以外
except that 后跟从句