定语从句就是把一个句子当形容词用，修饰前面的名词（先行词）。它是考研长难句里出现频率最高的修饰层——看到 who / which / that / whose / where，立刻知道后面是一段”长形容词”，先括起来不读主干。
PG003 · 02
02关系词选择与四种特殊形式
关系词
修饰对象 / 在从句中作
真题标志
who / whom
先行词指人；who 作主语，whom 作宾语
boy who went…; one George Scovell
which
先行词指物；可指前面整句话
a new social pattern which…
that
指人/物皆可，限定性；作宾语常省略
elements that lack…
whose
表”……的”，作定语
documents … whose secrets
where / when
先行词是地点/时间，在从句中作状语
Europe, where forestry…
介词+which
= where / when / why，正式书面
in which the division…（PG001例）
限定 vs 非限定：
· 限定性（无逗号）：去掉从句句子意思不完整，如 elements that lack commercial value（是”那些缺商业价值的”要素，不是别的）。
· 非限定性（有逗号）：补充说明，去掉句子仍完整，如 Europe, where forestry is more advanced, …。
· 分隔式：先行词与关系词被介词短语隔开，如 documents in code that had been captured——that 不修饰 code，而修饰 documents。
PG003 · 03
03真题例句（上）
例1 · 英一 2010 翻译(49) 非限定性 where
In Europe,where forestry is ecologically more advanced,the noncommercial tree species are recognized as members of the native forest community, to be preserved as such, within reason.
where… 有逗号，是非限定补充”在欧洲这个地方”；主干是树种被视为森林群落成员；绿色不定式 to be preserved 作补充说明。
例2 · 英一 2010 翻译(50) 双层 that 并列修饰同一先行词
It tends to ignore, and thus eventually to eliminate, many elements in the land communitythat lack commercial value, but that are essential to its healthy functioning.
两个 that 并列、都修饰 elements：缺乏商业价值、但对健康运转必不可少。中间 in the land community 是分隔，that 不修饰 community。
例3 · 英一 2012 翻译(49) which + that 双层嵌套
The second, by Joshua Greenberg, takes a more empirical approach to universality, identifying traits (particularly in word order) shared by many languages, which are considered to represent biases that result from cognitive constraints.
which 修饰前面的 traits；that result from… 又修饰 biases——一层套一层。读时从内往外翻：认知局限导致的偏见。
例4 · 英一 2013 翻译(48) 非限定 which + 地点 where
The gardens of the homeless, which are in effect homeless gardens, introduce form into an urban environment where it either didn’t exist or was not discernible as such.
It listed many documents in codethat had been captured from the French Army of Spain, and whose secrets had been revealed by the work of one George Scovell, an officer in British headquarters.
that… and whose… 并列修饰 documents（不是 code）：那些缴获的文件、以及它们的秘密。灰色 an officer… 是 George Scovell 的同位语。
例6 · 英一 2017 翻译(50) 限定性 which
It gives a basis to all organizationswhich seek to promote the learning and use of English, a basis for planning to meet possibilities of what could be a very different operating environment.
which seek to promote… 限定哪些 organizations；句末灰色是 a basis 的同位语，展开说明这个基础。
例7 · 英一 2018 翻译(47) who + which 双层
no boywho went to a grammar schoolcould be ignorantthat the drama was a form of literature which gave glory to Greece and Rome and might yet bring honor to England.
who went… 修饰 boy；which gave… 修饰 literature。主干 = no boy could be ignorant that…（双重否定：上过文法学校的男孩都知道）。
例8 · 英一 2015 翻译(48) which 中插入让步从句
the result was a new social patternwhich, although it resembled European society in many ways, had a character that was distinctly American.
which 从句里被 although… 插入打断，先跳过插入：which had a character。that was distinctly American 再修饰 character。
