为什么要使用人称代词呢?哪些情况下必须用?
如 The man whom I saw told me to come back today.
能写成这样吗?I saw the man told me to come back today.
还有The man who robbed her has been arrested.能改成另一种形式吗?
哪些情况必须使用人称代词呢?谢谢.