Which 的用法和判断

一、which 的基本用法

Ⅰ. which 作“哪一个”、“哪些”讲，当定语，用于疑问句和名词从句：

1. Which way can we carry out this test, this one or that one？我们能用哪种方法进行这个试验，这种还是那种方法？
2. There are many types of pagers in the shop. I don't know which one you like best. 商店里有许多寻呼机，我不知道你最喜欢哪一种型式。（which 引出宾语从句。）
3. He is worried about which English, British or American, he should teach. 他为教哪种英语——英国英语还是美国英语——而躁急。（介词宾语从句）
4. Under which conditions the machines work is an important question. 这些机器在哪些条件下操作是一个重要问题。（主语从句）
5. What we want to know is which computers sell well in the retail business. 我们想知道的是哪些计算机在零售中畅销。（表语从句）

II. 作“哪一个”、“哪些个”讲，作疑问代词用，用于疑问句和名词从句：

1. Which works better, this or that one? 哪台操作较好，这台还是那台？
2. Which of you will go with us? 你们中间哪一个（或哪些人）同我们一起走？
3. Tell us which of you are going. 告诉我们，你们哪些人要走。（宾语从句）
4. The choice of a production process depends on which of the products you want to obtain. 生产过程的选择取决于你想要获得其中哪个产品。（介词宾语从句）

III. which 作关系代词用，专指事物而言：

A. which 用于限制性定语从句中：

1. The machine which we are designing is a new-type drilling machine. 我们正在设计的那台机器是一台新型钻机。（which 在从句中作宾语用，并且还可省略。）
2. 《Computers》is a subject with which all the students have to be familiar. 《计算机》是一门所有学生都得熟悉的一门课程。（介词也可置于句末。）
3. The door of which you lost the key cannot be opened. 你丢失钥匙的那扇门开不了。（which 作介词 of 的宾语，但该介词短语又作 key 的定语。）
4. He will become the man which his parents want him to be. 他将成为他的家长所期望的那种人。

注：which 用于定语从句中一般指物。但当 which 在定语从句内作表语或宾语补语时，也可指人。如上句 4 和下面 B 项中第 5 句即是，不宜用 who 或 whom 代替。

1. Neither rain nor snow nor sleet keeps the postman from delivering our letters which we so much look forward to receiving. 雨、雪、冰雹都没使邮递员中断投递我们迫切盼望收到的信件。（句中 which 是句末动名词 receiving 的宾语。）

B. which 用于非限制性定语从句中，这时which前有逗号。

(a) which 代替主句中某个词或词组，并对它进行补充说明：

1. The meeting, which was held at our university, was a success. 那个会是在我校开的，获得了成功.
   试比较下列限制性定语从句：
   The sports-meeting which was held at our university was a success. 那次在我校开的运动会获得了成功。
2. Air is a mixture of gases, of which oxygen forms 21 percent by volume. 空气是一种气体混合物，在该混合物中氧气按体积计占 21%。（which 在非限制性定语从句中作 of 的宾语。）
3. She lived together with me last year, during which time she helped me with my lessons. 她去年和我住在一起，在这期间她帮助我学习功课。（which 在从句中作 time 的定语，然后 which time 作介词 during 的宾语。）
4. She is a good chemistry teacher, which indeed she is. 她是一位好的化学老师，实际上她确实如此。（which 在从句中作表语。）
5. He was surprised at the news, which I was not. 他对那消息感到惊讶，而我不惊讶。
6. But Edison had very little power in the great new company, which would never have been started without his invention. 但是爱迪生在这家新的大公司内没有什么权力，虽然这家公司没有他的发明就根本不能开业。（后面从句含有让步的意思。）
7. I had asked him to show me the IP phone, which he did. 我请他让我看看那台网络电话，而他就给我看了。（which 表示主句中 "to show…" 的内容。）根据上述例句不难看出，非限制性定语从句由于是作补充说明的，常分译为妥。

(b) which 代表主句中谓语的整个概念：

1. He can write a letter in English, which I cannot. 他能用英文写信，而我不能（which 代替 write a letter in English）
2. Metal will bear beating with a hammer, which a stone will not. 金属能经受住锤子的锤打，但石头不能。（which 代替 bear beating with a hammer.）
3. When deeply absorbed in work, which he often was, he would forget all other things. 他常常地聚精会神地工作，那时他常把其它所有事都忘了。

（which 代替 when 引出的时间状语从句中的谓语一部分“deeply absorbed in work”，而时间从句中省略了 he was。would 表示过去多次动作。本句未按原文结构翻译。）

(c) which 代表主句整个意思。若 which 在从句中作主语，其谓语为第三人称单数。which 有时代替主句中的某部分内容。例如：

1. She is very fond of her daughter, Emily, which is natural. 她非常爱她的女儿埃米莉，这是很自然的。（which 代表整个主句意思。）
2. Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽，这就叫做蒸发。（同上）
3. a. The refrigerator may be out of order, in which case it will be repaired at once. 冰箱可能发生故障。在本情况下要立即予以修理。（which 代替主句整个意思，但在句中作 case 的定语。）
   b. It is suspected that cancer may be a virus, in which case it can be treated by a vaccine. 人们猜疑癌可能是一种病毒，如果这样，就可用一种疫苗来治疗。（which 仅代表主句中的主语从句的内容。）
4. a. While he was in the army, he learned English, which helped him a lot in his work here. 当他在军队时学了英语，这对他在这里的工作有很大帮助。（which 代表前面主从复合句内容。）
   b. When he finds it hard to fall asleep, he starts worrying about his inability to sleep, which increases his insomnia, which increases his worries, which…. 当他发觉难于入睡时，就开始为不能睡眠而急躁，而急躁加重了失眠，失眠又加重了急躁…。（三个 which 代表各自前面的有关词语。）

C. 关系代词 which 用于不定式短语中，而该不定式短语作前面名词的后置定语。注意这个 which 一般是介词宾语，还常可省略。

1. There is no key with which to open the door. = There is no key to open the door with. 没有能打开这扇门的钥匙。
2. He must have some time in which to make the necessary preparations. 他一定要有一些时间来作些必要的准备。（句中 in which 还可省略。）
3. She reached Tianjin and decided it would be a good city in which to sell materials for building houses. 她到达天津并认定这是个适于销售建房材料的好城市。

二、判别 which 用法时注意事项

Ⅰ. which 或带 which 的介词短语前面有逗号的，则后面的定语从句为非限制性定语从句（见本节、III. B 各例句）。

II. 根据从句谓语的单复数和逻辑意义，来判断 which（在从句中作主语）同主句中哪个词或词组有关，是否代表主句整个意思。例如：

1. It was the discovery of definite facts like this about electricity which make it possible to build all sorts of electric instruments and machinery. 这是电方面与此类似的某些事实的发现，这些事实使各种电气仪表和机械的制造成为可能。（由于定语从句中谓语用 make, 表明 which 系指复数名词而言，故 which 不可能代替 electricity 或 discovery，只能说明复数名词 facts，而在逻辑上也讲得通。）
2. A calorie is the quantity of heat or energy which is necessary to raise the temperature of water from 15℃ to 16℃. 一卡就是把一克水的温度从 15℃ 提高到 16℃ 所需要的热量或能量。（which 后用 is，故只与前面单数名词有关。再从逻辑意义上考虑，which 代表 the quantity of heat or energy，而不是仅仅说明 heat 或 energy 的。）
3. Rubber is a light, elastic, durable and water-resistant material, which make rubber industry very important. 橡胶是一种质轻、富有弹性、经久耐用和防水的材料，因此（原意为“这就使得”）橡胶工业十分重要。（which 前有逗号，引出非限制性定语从句。从句谓语用 makes（单数第三人称）， which 可能代替前面的 material 或整个词组 a light… material，但也可能代表主句整个意思。语法分析这里已无能为力，只能从逻辑意义来进行判断。从意义上考虑，which 代表主句整个意思为宜。）
4. If the water is heated, the particles move quickly, which agrees with our theory. 如果把水加热，粒子运动就更快，这一现象是和我们的理论符合的。（同上）
5. Induction is a method of charging a conductor from a charged object which does not require bringing the two into contact. 电感应是带电物体对导体充电的方法，它并不要求这两个物体接触。（which 不代表靠近的 a charged object, a conductor 或 charging a conductor, 而代表 a method of… object 整个短语。必须进行逻辑判断。）
6. Some elements are known the atoms of which usually do not combine with more than one atom of any other element. 某些元素是众所周知的，它们的原子通常不能同任何其它元素的一个以上的原子相化合。（which 跨过主句谓语说明前面的主句主语 some elements，这种定语从句叫做“分裂式定语从句”，目的在于避免使带有定语从句的主语太长，从而导致“头重脚轻”。）

III. 注意对“介词+ which”的用法。

1. Work is the product of a force and a distance through which it acts. 功是力和在这个力作用下经过的距离的乘积。（it 是指“力”而言，故 which 只能代替前面的 a distance。）
2. Inertia is that property of matter because of which a force must be exerted on a body in order to accelerate it. 惯性是物质的一种性质，由于具有那种性质，要使物体加速，就必须对物体施加力。

注：在限制性定语从句内不仅作宾语的关系代词 which 可以省略，有时作介词宾语的 which，当其有关介词挪到定语从句句末时，也可省略。例如：

1）Air will completely fill any container (which) it may be placed in. 空气将完全填满可以在其内放入空气的任何容器。
2）They studied different types of air conditioners (which) we were making use of. 当时他们研究了我们正在使用的各种型式的空调器。

Ⅳ. 注意作定语的不定式短语中，介词省略了作其宾语的关系代词 which（详见本节、一、I. C）。

Ⅴ. 在修饰 distance, time 的限制性定语从句内，作状语的关系代词 which 也可省略。详见第 145 节、七。

1. The amount of work is equal to the product of a force by the distance (which) the body is moved in the direction of the force. 功的数值等于力和物体沿着力方向移动距离的乘积。
2. M is the number of times (which) X is as great as Y. M 等于 X 相当于 Y 的倍数。

Ⅵ. 注意在修饰 direction（方向）和 way（方法，途径）的限制性定语从句内，当以 in which 出现时，常常把 in which 省略。例如：

1. We can change the direction (in which) a force is acting. 一个力的作用方向我们是可以改变的。
2. The way (in which) this material can be used depends on its properties. 使该物质能得到应用的方法取决于该物质的性质。

Ⅶ. 当主句用“介词+名词”表示地点时，不要用“介词 + which”引出定语从句，而要用 where 引出定语从句。若该名词前无介词，则后面定语从句用“介词 + which”或 where 均可。例如：

1. The offices, laboratories, and museum are situated at the top of the hill where they command a fine view. 这些办公室、实验室和博物馆都位于山顶上，在这里可俯瞰美丽景色。
2. That was the town where (或 in which）he was born. 那是他出生的城镇。