who只能是指人，that，只能代物；
who,that都代指人时的区别：
只用that的情况：
a. 当先行词是最高级或被最高级所修饰时，只能用that引导定语从句。
b. 当先行词是序数词或被序数词所修饰时，只能用that引导定语从句。
c.当先行词被only, very, just, last, one of, all no, little, few, any等词修饰时，只能用that引导定语从句
d.当先行词既有人又有物时，只能用that引导定语从句
e.当先行词被the only, the very, the same, the last等词修饰时，只能用that引导定语从句。
只用who的情况：
⑴ 当先行词是one, ones, anyone, those指代人时， 只能用who
⑵ 在there be 结构中，先行词是人时，只能用who
⑶当先行词是人，后面有较长的修饰语时，只用who.
I met a friend of mine who had got three gold medals in the Asian Games.
⑷当先行词是I, you, he ,they等时（常用于谚语中），只用who.
He who plays with fire gets burned. 玩火自焚。
温馨提示：答案为网友推荐，仅供参考
