“介词＋关系代词”引导定语从句是学习定语从句的重点。学习这类从句时应注意以下几点：

首先，用于这类定语从句的关系代词一般为which（指物）和whom（指人）。其中，介词的选择非常重要，主要有四大原则：

1. 根据定语从句的谓语动词确定介词，与之构成动词短语。如“Is this the car for which you paid a high price?”即“pay for”。

2. 根据定语从句中的形容词确定介词，与之构成形容词短语。如“Two things about which Karl Marx was not sure were the grammar and some of the idioms.”即“be sure about”。

3. 根据修饰的先行词确定介词。如当先行词为表示时间、地点、原因等的词时，可用when, where, why替换。例如“I’ll never forget the day on which I joined the army.”“The factory in which his father works is far away from my hometown.”

4. 根据句子意思确定介词。例如，“This is the pilot for whom I bought a camera.”与“who”连接与“with whom my brother has worked for ten years.”与“who”连接表达的含义不同，前者表示“for”，后者表示“with”。

其次，介词若与从句中动词词组相关，可前置或后置。若与动词构成固定词组，则一般不前置。例如，“This is the very pen that I’m look for”。

在限定性定语从句中，介词前置时，必须用关系代词which / whom，且不能省略。反之，介词后置时可用that，也可省略。如“This is the school in which I studied 3 years ago.”

关于所属关系，介词多用of，关系代词为which / whom。例如“He lives in a room, the window of which faces west.”可以转换为“He lives in a room, whose window faces west.”

此外，当表达整体中的一部分或“中最”的含义时，介词同样常用of，如“He has two daughters, both of whom are college students.”

了解以上原则可以帮助掌握“介词＋关系代词”引导定语从句的正确用法。关注华慧考博可以帮助获取更多考博经验以及考博真题。华慧考博是一个专业的考博英语辅导机构，会及时更新全国各大院校博士招生简章，并提供考博英语真题、考博专业课真题等重要信息。由专业考博英语辅导团队为您设计考博英语复习计划，助力广大考生顺利考取博士。