Which用法

he(主语) saved(谓语) (缺宾语,补宾语,即前面的money)
helping the persons in trouble
这里用which,指物(money)

句子成分 用于限制从句或非限制性从句 只用于限制性从句

代替人 代替物 代替人或物

主语 Who which that

主语 Whom which that

宾语 Whose（=of whom） whose（=of which）

A. which
Which - 代物体，比方说句子中的which代替money，引导从句

Who - 谁：当先行词是一个或多个人或是被赋与身份的一个人时，用作关系代词来引导从句：He is a person who likes to play piano.

Whom - 作先行词，但是代替宾语：如I met the man whom need to be took care by hospital.

Whose - 作为所有格：I have a friend whose brother was dead last week.

A，他用他节省下来的大部分的钱来帮助处在困难的人。he saved是用来修饰money，是物。who是修饰人，he is a person who always makes troubles.whom是who的宾格，一般用whom是可以用who替换的，但who不一定能用whom替换。whose是who的所有格形式，He is a popular singer whose father is also a singer.