2. as 引导非限制性定语从句，指代 As everyone knows, Tom is good at
整个主句的内容，从句可置于句首， English. 句中和句尾。
as 引导非限制性定语从句 与which 的区别
He left her, as/ which was strange.
5. which 引导非限制定语从句，指代整
个主句的内容，从句只能置于句尾。 The decision was postponed,
which was exactly what he wanted.
与主句之间通常有逗号隔开，口语中使用时有停 顿。
功能上
用于对先行词的意义进行修饰、限制和识别， 用于对先行词起补充说明作用，如果省略，句意 如果去掉，就会造成句意不完整或概念不清； 仍然清楚、完整。
翻译上
翻译在它所修饰的先行词之前,如： He is the student whose leg was broken. 他就是那个词，也可以是短语或句子
that, why, which, who, whom, whose 引导词
2020/7/13 有时可以省略
that（极少见）which, who, whom, whose
一律不省略
5
1. 用于非限制性定语从句时，可以 指代整个主句的内容，as 和which 可以换用。
Many of our Irish people are going to settle in America, where land is
cheap.
我们爱尔兰人中，有许多都要迁居美国了，那里土地价格低廉。
I’m seeing the manager tomorrow, when he will be back from New York.
