which why that where who whom whose 在定语从句中怎么分别

Question

例如：若句子前有“，”后面用 which 而不用 that，用 whom 不用who以此为例

Answer 1

先行词是事，物用which
先行词是the
reason
用why
先行词是物，人时可以用that(代替who和which)
先行词是人，而且是主格时用who
先行词是人，而且是宾格是用whom
(口语中通常用who
代替whom,但是如果有介词相连就只能填whom)
当先行词前面的词与先行词后面的词成所属关系时用whose