You must reply to that boy who wrote you a letter 谁是主语
问题描述:
You must reply to that boy who wrote you a letter 谁是主语
能不能用whom
答
you
是主语.
You must reply to that boy who wrote you a letter
who wrote you a letter
分句里who 作主语,不可以换.
You must reply to that boy who/whom you wrote a letter.
这句可以,分句中作宾语