定语从句是英语学习的一个重要语法项目，也是英语考试的热点之一。小编下面主要跟大家分享下定语从句中引导词的选择技巧，供大家参考。

1. 根据引导词在定语从句中的语法功能进行选择。

① I will never forget the days when I stayed in Peking University.

② I will never forget the days which / that I spent in Peking University.

③ He is no longer the boy that he used to be.

句①中 stayed 是不及物动词，引导词 when 在从句中作时间状语。

句②中 spent 是及物动词，引导词 which / that 在从句中作 spent 的宾语。

句③中引导词 that 在从句中作表语。

2. 根据先行词及先行词前的修饰词来选择。

① This is the most beautiful place that I visited last year.

② This is the place which / that I visited last year.

句①中先行词 place 前有形容词最高级修饰，引导词只能用 that。

句②中先行词 place 前没有形容词最高级修饰，引导词用 which 或 that 均可。

要注意，在下列情况下只能用 that 而不能用 which。

(1)先行词前有序数词或形容词最高级修饰时。

例句：It's the first composition that I have written in English.

(2)先行词前有 any, all, few, little, the only, the right, the very, the last 等修饰时。

例句：You can take any seat that is free.

(3)先行词是不定代词 all, some, something, anything, nothing 等时。

例句：Is there anything that I can do for you?

( 4 )先行词中既有人又有物时。

例句：He told us the people and places that he had visited.

( 5 )在 there be 结构中，先行词指物时。

例句：There is a book on the desk that I am interested in.

( 6 )在由 which, who, whom 等开头的疑问句中。

例句：Which is the book that interests you most?

3. 根据引导词在定语从句中的位置及意义进行选择。

① Bamboo is hollow, which makes it very light.

② Taiwan, as is known to all, is a part of China.

③ As anybody can see, the elephant's nose is like a snake.

关系代词as和which在非限制性定语从句中均可指代主句的全部或部分内容。但 which 引导的非限制性定语从句只能放在句末，如句①，而as引导的非限制性定语从句既可放在句末，也可放在句中或句首，如句②和句③。另外，which引导的非限制性定语从句常与主句有种因果关系，可译作“所以”，语气不强时可不必译出。as引导的非限制性定语从句修饰整个主句时，往往与系动词搭配使用，可译作“这一点，正如”。

4. 根据定语从句的性质进行选择。

① The park, which we visited yesterday, is very beautiful.

② The park which / that we visited yesterday is very beautiful.

非限制性定语从句不能用 that 来引导，并且作宾语的引导词不能省略;而限制性定语从句不受限制。句①就是非限制性定语从句，故引导词只能用which，句②是限制性定语从句，故引导词用which或that均可。

5. 根据定语从句中介词所在的位置进行选择。

① This is the room in which I used to live.

② This is the room which / that I used to live in.

定语从句中如介词前置，作其宾语的引导词就不能用 that ，而只能用 which ，且不可省略，故句①只能用 which ;句②则用 which 或 that 均可，且可省略。但要注意，含有介词的短语动词一般不能将介词拆开前置，只能放在动词之后。

例句：The babies whom the nurses are looking after are very happy.

6. 关系代词 as 引导定语从句时，常与 the same, such, so 等搭配。

例句：He is doing the same work as I am.他正在做着和我一样的工作。

7. that 有时被用作关系副词，代替 in / on / for which ，并且常常被省略。

例句：The way ( that / in which ) you look at problem is wrong.