2009年12月大学英语四六级考试语法精要(六)

　　6.关系代词在限制性定语从句中常可以省略,一般有以下几种情况:

　　1) 关系代词在从句中作直接宾语时，在大多数情况下可以省略。

　　This is something (that) you must always keep in mind.

　　The man (whom) you just met is our manager.

　　关系代词作介词宾语时，介词位于句尾时关系代词可以省略;介词位于关系代词之前时则关系代词不能省略。

　　This is the room (which) Churchill was born in.

　　This is the room in which Churchill was born.(which不可省略)

　　2) 关系代词作主语时一般不能省略，但如果关系代词在由there … be存在句构成的定语从句中作主语时常可省略。

　　This is the only book (that) there is on this subject.

　　The old professor made full use of the time (that) there was left to him to continue his research.

　　3) 在way后面的定语从句中in which或that通常省略。

　　That’s the way (that/in which) I look at it.

　　I don’t like the way (that/in which) you laugh at her.

　　7.非限制性定语从句

　　非限制性定语从句修饰先行词或整个主句，起补充说明的作用，如果省略掉，原句句意仍保持完整。非限制性定语从句要用逗号与主句隔开，其引导词不能用that。非限制性定语从句属于正式语体。经常考到的非限制性定语从句有以下三种。

　　1) 由which、as引导的非限制性定语从句。which、as代表整个主句。

　　He said that he had never seen her before, which was not true.

　　China is still a developing country, which is known to all of us.

　　2) 由 “介词+关系代词”引导的非限制性定语从句。

　　He sent her a letter, in which he said that he was sorry for what he had done to her.

　　He failed to pass the exam, because of which his parents scolded him.

　　4) 由 “数词、代词或名词+of +关系代词”引导的非限制性定语从句。

　　He had three sons, one of whom was my son’s classmate.

　　There are about twenty students in this course, most of whom are freshmen.

　　They are two different words, the spellings of which are easily confused.