题目内容：

The mother didn't know who to blame for the broken glass as it happened while she was out.
为什么用who 而不用whom啊?

优质解答

who to blame 这个做宾语.Whom 只能出现在从句里面或是介词（如 to,from,at,of..）后面.1． Whom 出现在从句里面时,所有用whom的地方都可以用who代替.Whom 这个词只出现在很正式的书面语.口语不用.2． Whom 在介词（...