whom意思是：谁;(与who同义，作为动词或介词的宾语)什么人。
语法说明：
1、Whom is not used very often in spoken English. Who is usually used as the object pronoun, especially in questions. 在英语口语中，whom不常用，通常用who作宾格代词，尤其在疑问句中。
2、The use of whom as the pronoun after prepositions is very formal. whom作代词置于介词后的用法非常正式。
3、In spoken English it is much more natural to use who and put the preposition at the end of the sentence. 在英语口语中，疑问词用who，将介词置于句末更自然。
4、In defining relative clauses the object pronoun whom is not often used. You can either use who or that , or leave out the pronoun completely. 在限定性关系从句中，宾格代词whom不常用，可用who或that或干脆省去代词。
5、n non-defining relative clauses who or, more formally, whom (but not that ) is used and the pronoun cannot be left out. 在非限定性关系从句中，要用who或更正式的whom（但不能用that），而且此代词不能省略。
双语例句：
1、He asked me with whom I had discussed it.
他问我和谁讨论过此事。
2、To whom did she address the letter?
那封信她是写给谁的？
3、To whom should I address the letter?
这封信我该写给谁呢？
4、The author whom you criticized in your review has written a reply.
你在评论中批评的那位作者已经回信答复了。
5、Her mother, in whom she confided, said she would support her unconditionally.
她向母亲坦露心扉，母亲说将无条件地支持她。