who是对人的提问,一般几疑问句里当主语例如:who is Tom?也有时用于从句的连词. whom是who的宾格,一般用于介词和动词只后例如:for whom(为谁)不过现在who和whom用法已经不是很明显了,一般在口语里who都代替whom. whose是“谁的”意思,一般用于所有格的疑问例如:whose is the book? who's就是“who is的缩写”
who 是做主语成分 后面接动词 如 who did it? whom 是做宾语成分 动作的对象 如 whom did you give the pen to 如果改成祈使句就很明白 you gave the pen to whom( 宾语) whose 是 谁的? 后面+名词 whose book is this? 一般回答 my book, his book 什么的