a. 先行词的结构特点

i. 先行词是一个词

1. Remember that the best relationship is one where your love for each other is greater than your need each other.

ii. 先行词是一个短语

1. In Europe, as elsewhere, multi-media have been increasingly successful groups which bring together television, radio, newspapers, magazines and publishing houses that work in relation to one other.

iii. 先行词时一个分句

1. He said he had no time, which isn’t true.
2. The Greeks assumed that the structure of language had some connections with the process of thought, which took root in Europe long before realized how diverse languages could be.

iv. 先行词是一个完整的句子

1. My girlfriend likes dancing with other guys, which really drives me crazy.

b. 先行词的位置特点

i. 先行词+其他定语+定语从句 遵循尾重原则，结构复杂的定语置于其他定于后边，从而造成先行词隔离

1. Changes in the social structure may indirectly affect juvenile (青少年) crime rates. For example, changes in the economy that lead to fewer job opportunities for youth and rising unemployment in general make gainful employment increasingly difficult to obtain.

ii. 先行词+状语+定于从句

1. Politics is probably the only business in the world where they spend the most money when they have the least number of available customers to pitch to.

iii. 作主语的先行词+谓语部分+定语从句

1. Social science is that branch of intellectual which seeks to study humans and their endeavors in the same reasoned, orderly, systematic, and dispassioned manner that natural scientists used for the study of natural phenomena.

c. 如何判断先行词

i. 结合定语从句的意思
ii. 结合定语从句中的关键词
iii. 结合定语从句的谓语单复数
iv. 结合定语从句的关系词
v. 结合先行词的结构特点
vi. 结合先行词的位置特点

d. 介词+关系代词

i. 看从句选介词

1. 看从句的动词：所用介词须与从句中的动词构成固定搭配
   a. The buzzard can watch high in the sky the ground for signs of the waste and dead animals on which it feeds.
   b. On the whole such a conclusion can be drawn with a certain degree of confidence, but only if the child can be assumed to have had the same attitude towards the test as the others with whom he is being compared, and only if he was not punished by lack of relevant information which they possessed.
2. 看从句的形容词：所用介词须与定语从句中的形容词构成搭配
   a. Dolphins might be trained to cooperate with fishermen and help them by finding, tracking, herding, or even catching fish- in all of which activities dolphins are expert.
3. 看从句的名词：所用介词须与定语从句中的某个名词构成搭配
   a. Many hypersomniacs suffer from narcolepsy, for which the primary symptom is excessive daytime sleepiness.

ii. 看先行词选介词

1. The ease with which the fish can be collected from the shore has almost resulted in its extinction

iii. 比较

1. 介词在短语中的位置
   a. 根据定语从句判断介词，如：depend on, familiar with, attention to
   b. 根据先行词判断介词 with ease, at the rate, to the extent

iv. 看句意选介词

1. America’s capacity utilization, for example, has reached historically high levels earlier this year, and its jobless rate (5.6% in August) has fallen below most estimates of the natural rate of unemployment- the rate below which inflation has taken off in the past

v. 表示所属关系或部分与整体的关系时用介词of

1. This kind of support, like all government support, requires decisions about the appropriate recipients of the funds. Decisions based on utility as opposed to lack of utility are straightforward. But a decision among projects none of which has immediate utility is more difficult.

vi. 固定的介宾结构

1. in this case, in one’s honor, with one’s help 定语从句中变成 in which case, in whose honor, with whose help
2. We extended our warm welcome to the visiting delegation in whose honor a grand banquet was given.

vii. 定语从句的倒装 具体的结构时介词+关系代词+从句谓语+从句主语

1. They are groaning about soaring health budget, the fastest-growing component of which are pharmaceutical costs.

viii. “介词+关系代词+to do”结构

1. The farmer use wood to build a house in which to store grains.

e. 关系代词as

i. As引导非限制性定语从

1. As引导非限制性定语从句放在句首
   a. As is so often pointed out, knowledge is two-edged weapon which can be used equally for good or evil.
2. As引导的非限制性定于从句放在居中
   a. There is, as Rebert Rubin, the Treasury Secretary, says, a “disjunction” between the mass of business anecdote that points to a leap in productivity and the picture reflected by the statistics.
3. As 引导的非限制性定于从句可放在句末
   a. She has married again, as was expected.

ii. as 引导限制性定语从句 只能用在一些固定结构中，由 such, the same, as 等先行词的后面

1. As在定于从句中作主语
   a. The new map of the ocean floor shows the locations of twice as many undersea volcanoes as were previously thought to exist.
2. As在定于从句中作宾语
   a. It is likely that you will have such an exciting experience as Janet had a few years ago.
3. as 在定语从句中作表语
   a. He is not a fool as we would assume him to be.

f. 关系代词 than

i. Than 可作关系代词引导定于从句，在从句中一般作表语（也可作宾语）

ii. Than前面的主句需要有形容词的比较级形式

iii. 比较级所修饰的名词即为先行词。

iv. Don’t drink more wine is good for health.

v. These proposals sought to place greater restrictions on the use and copying of digital information than exist in traditional media.

g. 关系代词 but

i. 从but所表达的意思来看，But作关系代词具有否定意义，相当于that …not。 因此But后面接的定语从句在形式上是肯定的，但在意义上是否定的。

ii. But常与具有否定意义的主句连用。这样一来构成双重否定，表肯定

iii. But可指人也可指物，在句中表主语或宾语

iv. But通常只引导限定性定语从句

v. There are very few rules of grammars but have exceptions; the exceptions proves the rule.

vi. There is no man but errs.

h. 缩合关系代词what

i. 使用关系代词what的前提：what的前面不能有先行词 what 本身的含义里面已经有了一个“隐性”的先行词了。

ii. What的单独使用，及其后面不可以接名词 what单独使用=the thing/person that

1. Today’s vessel can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught.

iii. What 的后面可以接名词 what + 名词 = all the +名词+that

1. After sharing what little food they had , the old couple let the two angels sleep in their bed where they could have a good night’s rest.

iv. What用在一些固定的结构中 比如“所谓的”what is called, what can be called, what we call, what used to call. 还有一些做插入语的，一般放在动词或介词后面作宾语 what they described as, what they regarded as, what you may see as

1. The very people responsible for ushering in what some have called a “technological renaissance” say they are working longer hours, feel more stressed, are more impatient and are even less civil in their dealing with colleagues and friends – not to mention strangers.

i. 关系副词when

i. 注意

1. 用when 引导定语从句，其先行词必须是表示时间的名词
2. 先行词必须是day, year, time等
3. 可引导限定性和非限定性定语从句
4. April Fool’s Day is that special day of the year when you should play a joke on someone! Children’s favorites are to put salt in the sugar bowl for Dad’s morning coffee or put chalk on a desk at school so the teacher gets a white backside! But remember, if you play a joke after 12 noon, YOU are the April Fool!

ii. 先行词表示时间时，不一定都用when引导定语从句 在从句中缺少主语和和宾语时用which 和that

1. I’ll never forget the time which I spent on campus

iii. 如何区分when引导的定语从句与when引导的事件状语从句

1. 结构上不同 引导定语从句 when前面必有表示时间的名词，即先行词。When 引导时间状语从句往往没有表示时间的名词
2. When的作用不用 引导定语从句时，指代表示时间的先行词，在定语从句中作时间状语。 当when引导时间状语从句时，此时when不作任何成分
3. When的译法不同
4. Person has pieced together the work of hundreds of researchers around the world to produce a unique millennium technology calendar that gives the latest dates when we can expect hundreds of key breakthrough and discoveries to take place.

j. 关系副词where

i. 注意

1. 用where引导定语从句，其先行词通常是表示地点的名词
2. 其前面的先行词时表示地点的名词，如place, house等
3. 可引导限定性和非限定性从句

ii. 先行词表示地点，不一定都用where引导定语从句 在从句中缺少主语和和宾语时用which 和that

1. In fact, there are now so many deer that some are being sent to places which would like to return this kind of deer to the wild.

iii. Where 引导定语从句，先行词可以使含有地点意义的其他各种名词

1. Both the United States and China had reached a point in history where they shared an eagerness to start a new relationship, and where both were prepared to pay an ideological price for it.

iv. 如何区分where引导的地点状语从句和定语从句

1. 结构上不同 先行词必然表示有地点的名词
2. Where的作用不同

k. 关系副词why

i. 注意：

1. Why 在定语从句中作原因状语，修饰从句的谓语动词
2. 其先行词必须是表示原因的名词，如reason，cause等
3. 只引导限定性从句。
4. The online shopping is becoming more and more popular in China. It either takes the form of B2C or C2C. The major reasons why growth is slow are first, concerns about security and reliability and second, Chinese customers are used to haggling over prices in stores, a process which does not transfer to the Internet.

l. 关系副词有how么？

i. How不可以作为表示方式的关系副词。表示方式可以用下面这四种句型

1. The way + 从句
2. The way that +从句
3. The way in which +从句
4. The manner that +从句
5. Confidence is probably one of the most noticeable traits in the Americans. They show confidence in the way they talk, the way they smile, the way they dress and the way they walk.

m. 带有插入语的定语从句

i. 定语从句的关系词后面插入一个主谓结构

1. 作主语的关系词+插入语+定语从句的谓语部分
   a. Hilton is building its own hotel there, which you may be sure will be decorated with Hamlet Hamburger Bars, the Lear Lounge, the Banquo Banqueting Room, and so forth, and will be very expensive.
2. 作宾语的关系词+插入语+定语从句的主谓部分
   a. What is harder to establish is whether the productivity revolution that businessmen assume they are presiding over is for real.
3. What 引导的从句中带一个主谓结构的插入语
   a. There was a very interesting remark in a book by an Englishman that I read recently giving that what he thought was a reason for this American characteristic.

ii. 定语从句的关系词后面插入一个其他成分

1. Real friends are those who, when you’ve made a fool of yourself, don’t feel that you’ve done a permanent job.

n. 并列定语从句 通过and, but, or等并列连词连接共同修饰一个先行词

i. When we honestly ask ourselves which person in our lives means the most to us, we often find that it is those who, instead of giving much advice, solutions, or cures, have chosen rather to share our pain and touch our wounds with a gentle and tender hand. The friend who can be silent with us in a moment of despair or confusion, who can stay with us in an honor of grief and bereavement, who can tolerate not knowing, not curing, not healing and face with us the reality of our powerlessness, that is a friend who cares.

ii. 双层定语从句

1. There is nothing you can do, achieve , or buy that will outshine the peace, joy and happiness of being in communication with the partner you love.