1. 你一定要读的原版文章
本期开始，一律选取新闻篇章来作解析和阐述。一则为了确保文章质量，培养地道语感；二来培养阅读习惯，因为阅读才是提升英语的根本。所以想要提升英语水平的同学，一定要大量地阅读，让阅读开拓你的视野，扩展你的词汇，培养你的素养。
本期文章选自VOA慢速英语网This is America的Why We Take ‘Selfies’。讲述了人类热爱自拍背后的科学原理。下面将里面出现的定语从句进行罗列，或是改编以呈现部分定语从句。
People who post selfies and use editing software to make themselves look better show behavior connected to narcissism, the Syracuse researchers said.
There are other reasons, besides narcissism, that people post selfies.
She said some people that feel “peer pressure” like to post selfies. And some follow the popular belief that if there is no picture of an event or experience, it did not really happen, which is really hard for some to understand.
2. 句子解剖
从本质上讲，定语从句就是一个形容词，翻译成中文为“的”，只不过定语从句翻译起来会比形容词直接翻译更加复杂。不过我们可以灵活翻译。
比如Wang Nima is an interesting person. 王尼玛是个很有趣的人。
可以写成Wang Nima is a person who is interesting. 意思是一样的，但是“有趣的”原来是一个形容词来充当，后面这句变成了一个从句，句子。
为什么要这样画蛇添足？因为并不是所有的修饰成分都能用“......的”来表达。比如你要说，王尼玛是一个广东话讲的很好的人。你就找不到一个形容词来描述粗体部分了。这时，定语从句就可以大显身手了。
Wang Nima is a person who can speak Cantonese well.
所以定语从句还是要认真学习的，可以帮助你表达更丰富的意思和观点，让你飞。
3. 定从内功大法
定语从句有多种分类。普通大众了解两种就可以。
一是限定性和非限定性从句的区别，限定的没有逗号，非限定性有逗号，不能用that。
比如，Wang Nima is a person who is interesting. 是限定性定语从句，特别说明王尼玛的特质。
比如，Wang Nima is an interesting person, which is known by us. 是非限定性，拿掉之后，不影响原句的意思完整度。
另一种分类是根据关系词分，一种是关系代词引导，一种是关系副词引导。
关系代词主要指代名词或代词，充当主语、宾语、表语等主干成分。that指人或指物，who指人（主语），whom也指人（宾语），which指代物。whose表示“...的”，作定语。
比如Wang Nima is a person who is interesting. who作is的主语，指代person。
Wang Nima is popular person, whose program is quite famous in China. whose指代person's。
关系副词主要指代各种状语，尤其是强调时间、原因、地点等时。那自然对应的就是when，why和where了。
比如刚才的例句There are other reasons, besides narcissism, that people post selfies. that实际上就可以用why来替换，强调还有其他的人们为什么自拍的原因。因为是口语中的句子，that实际上并不是规范用法，尽量用why。
比如I came to Beijing where a lot of people live. 我去了北京，在北京，很多人住在那里。关系副词实际上相当于对应的介词加上which（which指代前面的名词）。所以这句可以变成 I came to Beijing in which a lot of people live.
这个实际上是很难的语法点。必须要在实战中才能体会。
最后，我们看看原文中的三个含有定语从句的句子。
People who post selfies and use editing software to make themselves look better show behavior connected to narcissism, the Syracuse researchers said.
who指代people，强调那些喜欢发自拍并用编辑软件把自己美化的人，实际上表露的行为和自恋是紧密相关的。这可是科学研究发现的。关系代词who引导一个限定性定从。
There are other reasons, besides narcissism, that/why people post selfies.
刚才已讲过，不再赘述。that相当于why，关系副词why引导非限定定从。
She said some people that feel “peer pressure” like to post selfies. And some follow the popular belief that if there is no picture of an event or experience, it did not really happen, which is really hard for some to understand.
第一个that引导限定性定从，说明前面提到的人们是感受到“同龄人压力”的人们，that为关系代词。后面一个which引导非限定定从，说明这件事让有的人很难理解，which为关系代词，指代前面“如果不贴图，就不能说明自己经历过一件事”的这种行为。
当然，定语从句还有一些特例，一些只能用that的情况。比如最高级后面，序数词后面，指人又指物，不定代词后等等。这个就不再详细阐述了。
4. 定从终极牛逼句
学会这一句，定语从句就基本不用再读语法书了。
I am a boy who enjoys reading The Kite Runner which is a popular book that was published in 2003 when I was only 12 and brought up in Jiangxi where my father had been living there for 20 years, which is known by many relatives and is the reason why I still do not like staying in Guangdong.
这里把所有的关系代词和关系副词都囊括了。你如果看得懂，或者背下来，定从就彻底搞懂了。