关系代词引导的定语从句

1) 由 that 引导的定语从句
that 可以指人或物。 在定语从句中作主语、宾语或表语， 作宾语或表语时可以省略。
* The man that visited our school is from Australia．到访我们学校的那个人来自澳大利亚。
* Is oxygen the only gas that helps fire burn? 氧气是唯一的助燃气体吗？
* The girl (that) I saw is called Mary. 我见到的那个女孩名叫玛丽。
* Is there anything else (that) you require? 你还需要别的东西吗？
* My hometown is no longer the place (that) it used to be. 我的家乡再也不是以前那个样子了。

2）由 which 引导的定语从句
which 指物， 在定语从句中作主语或宾语。
* I do not like stories which have unhappy endings.我不喜欢有不幸结局的小说。
* That was a fault which could not be forgiven. 那是不能饶恕的错误。
* Have you seen the watch (which) I left here just now? 你看到我刚才放在这里的手表了吗？
* These are the wires with which different machines are connected. 这些是连接不同机器的电线。
* The reason for which he refused to go to the party was that they had not invited him to. 他拒绝去赴宴的原因是他没受到他们的邀请。

3）由 who 引导的定语从句
who 指人，在定语从句中作主语。
* Anybody who breaks the laws will be punished. 任何违反法律的人都将受到惩罚。
* Do you know the boys who are standing over there? 你认识站在那边的那些男孩吗？

[注] 在口语中，可以用who代替whom, 在定语从句中作宾语。
* The man who I saw told me to wait. 我见到的那个人叫我等。
* I know the man who you were speaking to just now. 我认识你刚刚和他讲话的那个人。

4）由 whom引导的定语从句
whom 指人，在定语从句中作宾语或表语。
* The doctor whom you are waiting for has left. 你一直在等的那位医生已经离开了。
* Is she the very person whom we must take good care of? 她就是那个我们必须好好照顾的人吗？
* They are looking for the patient on whom doctors just performed an operation. 他们正在寻找那位医生刚刚给他做过手术的病人。

5）由 whose引导的定语从句
whose 通常指人，也可指物，在定语从句中作定语。
* There are some students whose questions I can't answer. 有些学生的问题我回答不了。
* They lived in a room whose window opened to the south. 他们住在一间窗户朝南开的房间里。
* Once there was a wise king whose name was Alfred. 从前有一个明智的叫阿尔弗雷德的英国国王。
* Can you see the mountain whose top is covered with snow? 你看得见山顶上覆盖着雪的那座山吗？