托福閱讀形容詞性從句解析

　　定語從句(Attributive Clauses)在句中作定語，其作用是修飾主句的某個名詞性成分，相當于形容詞，所以又稱為形容詞性從句。通常定語從句皆置于它所修飾的名詞或代詞之后，被修飾的名詞或代詞叫做先行詞(antecedent)，而引導(dǎo)定語從句的詞稱為關(guān)聯(lián)詞。

　　關(guān)聯(lián)詞常有3個作用：連接作用，引導(dǎo)定語從句;代替先行詞;在定語從句中擔當一個成分。關(guān)聯(lián)詞為關(guān)系代詞和關(guān)系副詞。關(guān)系代詞在定語從句中可以用作主語、賓語、定語等;關(guān)系副詞在定語從句中只用作狀語。如：

　　★ One factor which may help ensure that some endangered languages do not die out completely is people's increasing appreciation of their cultural identity.(which may help ensure that some endangered languages do not die out completely是關(guān)系代詞which引導(dǎo)的定語從句，用以修飾which的先行詞factor, which在從句中用作主語)

　　★ And even in regions where new projects seem warranted, we must find ways to meet demands with fewer resources, respecting ecological criteria and to a smaller budget.(where new projects seem warranted是關(guān)系副詞where引導(dǎo)的定語從句，用以修飾where的先行詞regions, where在從句中用作地點狀語)

　　定語從句一般緊跟在其先行詞之后。如：

　　★ Food production has kept pace with soaring populations mainly because of the expansion of artificial irrigation systems that make possible the growth of 40% of the world's food.(關(guān)系代詞that引導(dǎo)的定語從句緊跟其先行詞artificial irrigation systems之后)

　　有時也可以與先行詞分離。如：

　　★ A new teacher will come tomorrow, who will teach you Chinese.(關(guān)系代詞who引導(dǎo)的定語從句與其先行詞teacher分離)

　　用作關(guān)聯(lián)詞的關(guān)系代詞有that, which, who, whom, whose, as等，但在此提醒考生們絕對沒有“what”。who, whom, whose指人，who是主格，在定語從句中用作主語(在非正式英語中也可以用作賓語，并且用作賓語時可以省去不用);whom是賓格，在定語從句中用作賓語(也可以省去不用);whose是屬格，在定語從句中用作定語(有時也可以指物)。如：

　　★ The American zoologist Donald Griffin, who was largely responsible for the discovery of sonar in bats, coined the term ‘echolocation' to cover both sonar and radar, whether used by animals or by human instruments.(主格關(guān)系代詞who在從句中作主語)

　　★ The man who he talked about is a professor.(在非正式英語中who代替了whom,也可以省去不用)

　　★ He doesn't like the girl whom you refer to.(賓格關(guān)系代詞whom在從句中用作賓語，也可以省去不用)

　　★ The children whose parents give priority to work may feel lonely and alienated.(屬格關(guān)系代詞whose在定語從句中用作定語，指人)

　　★ The car whose wheels have been stolen was bought yesterday.(屬格關(guān)系代詞whose在定語從句中用作定語，指物，即car，可以用of which代替，但后者較為正式)

　　That在定語從句中既可以用作主語，也可以用作賓語(在非正式文體中可省去);既可以指人，也可以指物。如：

　　★ These methods include strength training that duplicate what they are doing in their running events as well as plyometrics, a technique pioneered in the former Soviet Union.(關(guān)系代詞that在定語從句中用作主語，指物)

　　★ Put another way, basic heath-care is now recognized as a ‘public good', rather than a ‘private good' that one is expected to buy for oneself.(關(guān)系代詞that在定語從句中用作賓語，指物)

　　★ The students that hold a foreign degree seem to be more confident and independent.(關(guān)系代詞that在定語從句中用作主語，指人)

　　which在定語從句中既可以用作主語，也可以用作賓語;一般皆指物(在非正式文體中可省去)。如：

　　★ Eye position in freshwater dolphins, which often swim on their side or upside down while feeding, suggests that what vision they have stereoscopic forward and upward.(關(guān)系代詞which在定語從句中用作主語)

　　★ Those surveyed had experienced chronic illnesses, for which orthodox medicine had been able to provide little relief.(關(guān)系代詞which在定語從句中用作賓語，可以省去)

　　which在從句中也可以被用作定語和表語。如：

　　★ His money had been stolen, which news annoyed him.(關(guān)系代詞which在定語從句中用作定語)

　　★ They were completely mistrusted, which in fact, they were.(關(guān)系代詞which在定語從句中用作表語)

　　關(guān)系代詞在從句中用作介詞賓語時，介詞可以位于從句之首，也可以位于從句之末。但以位于從句之首較為正式。如：

　　★ This has been encouraged through programs of language classes fro children and through ‘apprentice' scheme, in which the endangered language is used as the medium of instruction to teach people a traditional skill.(關(guān)系代詞which在定語從句中用作介詞in的賓語，介詞位于定語從句之首，即which之前)

　　★ This has been encouraged through programs of language classes fro children and through ‘apprentice' scheme, which the endangered language is used as the medium of instruction to teach people a traditional skill in.(介詞in位于定語從句之首，which在此可以省去)

　　像during, except或者表示分割作用的of等介詞通常放在關(guān)系代詞的前面。如：

　　★ The years during which he was away were long years to her.

　　★ He wrote many books, some of which you will read some day.

　　關(guān)系代詞who和that用作介詞賓語時，介詞須置于句末。如：

　　★ The writer you referred to was an unknown writer.(關(guān)系代詞who用作介詞to的賓語，介詞to須位于定語從句之末，who在口語中可以省去)

　　★ This is the problem that he has been complaining about.(關(guān)系代詞that用作介詞about的賓語，介詞about須位于定語從句之末)

　　有時定語從句中還有其他成分，介詞則位于定語從句之中。如：

　　This is the engineer who he cooperated with in the project.

　　先行詞指人時，關(guān)系代詞既可以用who, 也可以用that。但關(guān)系代詞在定語從句中用作主語時，多用主格who。如：

　　★ Beyond the practical need to make order out of chaos, the rise of the dictionaries is associated with the rise of the English middle class, who were anxious to define and circumscribe the various world to conquer.(persons, those, people等先行詞多用關(guān)系代詞who)

　　★ It is Tom who should be punished.(在強調(diào)結(jié)構(gòu)中，指人時多用who)

　　★ The American zoologist Donald Griffin, who was largely responsible for the discovery of sonar in bats, coined the term ‘echolocation' to cover both sonar and radar, whether used by animals or by human instruments.