2021军队职称英语考试指导：常用语法精解(13)

介词+which(whom)
先看两个句子：
This is the house.He has lived in the house for over 30 years.
变为↓定语从句
This is the house in which he has lived for over 30 years.
上述句子中，先行词在从句中充当介词宾语，形成"介词+which/whom"的形式，考试时要求作出1)要不要介词;2)若要，使用什么介词的判断。由于英语中介词搭配多为习惯用法，没有多少规律可循，因此这是定语从句考试的一个难点。
记住四个字：瞻前顾后
瞻前：先看看先行词一般与什么介词搭配，例如：
There are occasions _____ which joking is not permissible.
→Joking is not permissible _____(certain)occasions.
常与occasion搭配的介词是什么?on，即：
Joking is not permissible on(certain)occasions.(有的场合是不容许开玩笑的。)
↓
There are occasions on which joking is not permissible.
顾后：看看谓语动词常与什么介词搭配，例如：
This car,____ which I paid a lot of money,is now out of date.
→I paid a lot of money ______ this car.
Pay(money)for something是一个固定的搭配，因此应填介词"for"
当A、B、C、D中出现"介词+which/whom"选项时，而你又确实看不懂时，应倾向于选择"介词+which/whom"的形式，例如：
The two elements _____ water is made are the gases oxygen and hydrogen.
A.that
B.which
C.with which
D.of which
倾向选择C、D;正确答案D，"be made of"(由…组成):
The two elements are gases(oxygen and hydrogen).
Water is made of the two elements.
两个句子一合并，便是该句选择。
(四)其他应注意的确问题：
(1)同位语从句只能用"that"连接
常见的同位语先行词有：fact(事实),possibility(可能),idea(想法),belief(相信),doubt(疑问),news(消息),order(命令),promise(承诺),evidence(证据),suggestion(建议)等，例如：
Is there any possibility that all the villagers can send their children to school?(有没有这种可能，所有村民都能送他们的孩子上学?)
There can be no doubt that he is a qualified doctor.(毫无疑问，他是个合格的医生。)
(2)"as"也可以做关系代词用于连接定语从句，特别是在"such…as…","the same as…"以及"正如…"的结构中，例如：
I have never seen a thing as he described.(我从未见过他所描述的那种事。)
As was expected,the performance was a great success.(正如所料，演出获得了巨大成功。)
把该句理解为：The performance was a great success,which was expected，就比较容易理解as的这种用法。
将定语从句的连接用三句话归纳一下：
↗人用who/whom
(1)先行词在从句中当主、宾、表语→定语用whose
↘物用that(=which)/非限制用which
↗地点状语用：where
(2)先行词在从句中当→原因状语(reason)用：why
↘时间状语用：when
(3)介词+which/whom结构：瞻前顾后