whom

关于whom和who的区别，参见who 1

2.whom不用来指船，如不可说The ship whom you saw this morning will sail tomorrow，该把whom改作which。参见which 2 (4)和who 3

3.whom不可用作间接宾语，下面每组里的第一句和第二句都对，第三句不对：

• Whom did you give the letter to?
  To whom did you give the letter?
  Whom did you give the letter?
• Whom has she bought the book for?
  For whom has she bought the book?
  Whom has she bought the book?
• The man whom I gave the letter to is the secretary.
  The man to whom I gave the letter is the secretary.
  The man whom I gave the letter is the secretary.
• The boy whom she has bought the book for is her nephew.
  The boy for whom she has bought the book is her nephew.
  The boy whom she has bought the book is her nephew.

下面两点该注意：

（1）虽然可以说I gave him the letter和She has bought him a book，第一组和第二组里的第三句却不可说。

（2）第三组和第四组里的第三句都不对，假使把whom省去了也不对。

4.下面四句意思相同：

• He is a man whom to know is to love.
• He is a man to know whom is to love him.
• He is a man whom to know him is to love.
• He is a man whom to know is to love him.

第一句里的whom同时做know和love的宾语，严格地说不合语法，但这句最合习惯、最自然。其他的三句都合乎语法，但不合习惯。