一． 课前思考：
定语是什么？定语从句是什么及其构成？
定(限定/缩小范围)语:adj
定语从句:adj写成一句话
用一个形容词作定语修饰名词或代词。若要表达更复杂的意思，需借助一个句子
来修饰名词。
定语从句理解及其构成：
1.形容词作定语与从句作定语的比较
- I don’t like lazy peoples.
- I don’t like people who don’t love their own country.
定语从句构成、先行词和关系词
构成：
先行词+关系词+定语从句
各个词语解释：
先行词:被修饰的名词/代词，总在定语从句前面
关系词作用:连接主句和从句,指代先行词,在定语从句中充当一定成分的词
定语从句:不完整的句子
先行词
可以是：
1） 一个词
2） 一个短语
3） 一个句子
- Another trend that looks significant in 2015 is that America’s largest population group,Millennials (千禧一代)， will continue to put off buying a house. (2017-06 阅读)
主语+that，而且that在后面句子是作为主语（作为成分的），用来修饰主语，
所以是定语从句；“is”才与前面主语“trend”构成 主+系 ，然后后面又是that+
一个完整的句子，系表，所以是一个表语从句；“put off”后就正常接宾语。
- Living in an urban area with green spaces has a long-lasting impact on people’s mental well-being, UK researchers found moving to a green space had a sustained positive effect, unlike pay rises or promotion, which only provided a short-term boost. (2018-06)
“has”后面是一个名词，没毛病是正常的 谓宾；“found”后面不只是一个名词，而是
一个完整的句子，所以这是一个宾语从句；接着“which”后面不是一个完整的句子，
且which在句子中有一定成分，which前面又是名词，代入发现which指代的就是前面
的“pay rises or promotion”，形容这个名词，所以这是一个定语从句。
问题: according to one study, what do green spaces do to people?
A) improve their workefficiency
B) add to their sustained happiness //提高建立幸福感
C) help them build a positive attitude towards life.
自己选错了，选了C，并没有讲对于生活的，只能说有积极影响。
D) Lessen their concerns about material well-being
- And exercise releases hormones that can improve mood and relieve stress, which can also help learning.(2016-06)
首先，“that”后面不是一个完整的句子，所以不是名词性从句，然后结合
“hormones”，所以它是个定语从句修饰hormones；然后which后也不是一个完整
的句子（即which在句子中充当成分），然后根据判断，which是指前面那一个
句子。
which = exercise releases hormones that can improve mood and relieve
stress
which 译成:这
关系词
关系词:连接主句和从句,指代先行词,在定语从句中充当一定成分的词
关系词分为：关系代词 和 关系副词（具体在下个标题详说）
关系代词及关系副词有哪些？如何选择合适的关系词？
关系代词（在从句中充当成分）
We found that for some lottery( 彩 票 ) winners who had won more than 500,000 pounds the positive effect was definitely there, but after six months to a year, they were back to the baseline (2018-06 text1)
that后面接完整句子，宾语从句。
who接不完整句子，定语从句。
特殊的结构：介词+关系代词
Furthermore, humans have the ability to modify the environment in which they live. （ 考 研2003年翻译）
先行词＋介词+which/whom
这种其实也不特殊，之所以有个介词in是因为live in才要的。
Furthermore, humans have the ability to modify the environment
in which(in which = where) they live.
关系副词（在从句中不充当成分）
关系副词:when、where、why
时间名词+when;
地点名词+where ;
reason + why
定语从句——关系副词when
Our schools need both the talent and the organization to educate each child who arrives at the school door. Some show up ready, but many do not at this critical time when young brains are developing rapidly.(2016-06)
who后接不完整句子（关系代词），定语从句。
when后接完整句子（关系副词），形容time，定语从句。
定语从句——关系副词where
Recently I attended several meetings where we talked about ways to retain students and keep younger faculty members from going elsewhere.(2016-12)
The center of American automobile innovation has in the past decade moved 2,000 miles away. It has migrated from Detroit to Silicon Valley, where self-driving vehicles are coming to life.（2019-06）
定语从句——关系副词why
why 用来表原因，只引导限制性定语从句，先行词是 reason 等表示原因的名词。
This is the reason why I was absent from that meeting.
The reasons why I recommend Beijing can be listed as follows. (2019-12 作文)
限定性定语从句与非限定性定语从句如何区分？
1. 限定性定语从句
若去掉限定性定语从句，则主句部分的意思不明确，或意义不完整，所以不能用逗号
来分隔先 行词和定语从句。
2.非限定性定语从句
非限定性定语从句用来提供附加的而非必要的信息，只是对先行词作进一步解释、补
充和说明。 若去掉此定语从句，整个主句的意义一样很明确，不会引起误解和歧义。
非限定性定语从句：
The cab drivers, who knew about the traffic jam, took another road.
出租司机都换了另一条路，出租司机都知道那里堵车了
限定性定语从句：
The cab drivers who knew about the traffic jam took another road.
出租司机们都知道那里堵车了，所以他们都换了另一条路。
从上得出结论：
限定：这个意思就是 形容某个人或物 来 限定出某些人或物。
再结合上面来说：
第一句：“drivers”、“who”中间隔了逗号，表明了并没有进行限定，只是who来
代表“driver”罢了，然后这个句子就相当于一个并列句的另一个写法。
第二句：“drivers”、“who”中间没有逗号，表明了直接就进行限定了，表明了
这些司机是“知道会堵车的司机”，然后他们开了另一条路。
另一个例子：
非限定性：
Yesterday，I met your mom , who was shopping at the supermarket
at that time.
昨天，我遇到了你妈妈，她当时正在超市购物。
限定性：
Yesterday，I met your mom who was shopping at the supermarket
at that time.
昨天，我遇到了你 那个当时正在超市购物 的妈妈。
定语从句与同位语从句如何区分？
例句1：The news that you heard is not true.
定从:你听说的新闻不是真的。
定语从句中关系词that有含义，在从句中充当句子成分。
例句2：The news that Lincoln was murdered at a theater is true.
同位语从句:林肯在剧院遭到谋杀的新闻是真的。
同位语从句中那个无含义，不充当句子成分。
The fact that artisans, who were looked on as mechanics or skilled workers in the eighteenth century, are frequently considered artists today is directly attributable to the Arts and Crafts Movement of the nineteenth century.
句子结构：
主｛that同位语从句：主[who 非限定性定语从句：主谓宾] + 谓 + 宾｝+系+表