Who、Which、That：关系从句简单讲解
「The man who I saw.」 「The book which I read.」 「The car that broke down.」 关系从句让你将想法合并成一个句子——但who、which和that的规则连高级学习者都会搞混。本指南详细解释一切。
什么是关系从句？（简单解释）
关系从句是句子的一部分，提供关于名词的更多信息。它以关系代词开头——who、which、that、whose、where或when——像形容词一样修饰前面的名词。
没有关系从句，每个细节你都需要两个单独的句子。它们是将复杂英语粘合在一起的胶水，母语者不假思索地持续使用它们。
两个独立句子
I met a woman. She speaks five languages.
用关系从句合并
I met a woman who speaks five languages.
两个独立句子
She bought a laptop. It was very expensive.
用关系从句合并
She bought a laptop which/that was very expensive.
关系从句总是紧跟在它所描述的名词之后。'I met a woman who speaks five languages'——'who speaks five languages'描述的是'woman'，不是'I'。
Who、Which、That：基本规则
在who、which和that之间的选择取决于名词是什么——人、物还是两者皆可。这是覆盖90%情况的核心规则。
WHO——用于人
The teacher who taught me English was from London.
当名词是人（或人们）时使用'who'。
WHICH——用于物和动物
The book which I borrowed was fascinating.
当名词是物、动物或概念时使用'which'。
THAT——用于人或物
The teacher that taught me was great. / The book that I read was long.
'That'最灵活——在限定性从句中对人和物都适用。
在日常口语和非正式写作中，'that'比'which'用于物时更常见。在美式英语中，'The movie that I watched'比'The movie which I watched'听起来更自然。
限定性从句：必要信息（不加逗号）
限定性关系从句（也叫restrictive clause）提供必要信息。没有它，句子没有意义或意思完全不同。限定性从句没有逗号。
关键测试：如果你去掉从句，句子还能识别名词吗？如果不能，就是限定性从句。
The students who passed the exam were happy.
哪些学生？通过考试的那些。没有从句，我们不知道是哪些学生。
The restaurant that we went to last night was excellent.
哪个餐厅？我们昨晚去的那个。从句识别了它。
People who exercise regularly live longer.
不是所有人——特指经常运动的人。从句限制了含义。
限定性从句规则
从句周围不加逗号
可以使用who、which或that
美式英语中对物优先使用'that'
关系代词通常可以省略（见第5节）
非限定性从句：附加信息（加逗号）
非限定性关系从句（也叫non-restrictive clause）添加非必要的附加信息。名词已经被识别——从句只是添加额外细节。非限定性从句总是有逗号。
关键测试：如果你去掉从句，句子还有完整意义并能识别名词吗？如果是，就是非限定性从句。
My sister, who lives in Paris, is a doctor.
你已经知道哪个姐妹（我只有一个）。'who lives in Paris'是额外信息。
The Eiffel Tower, which was built in 1889, attracts millions of tourists.
只有一座埃菲尔铁塔。'which was built in 1889'是附加信息。
My car, which I bought last year, has already broken down.
你知道哪辆车（我的车）。从句添加了我何时买的。
非限定性从句规则
总是使用逗号（从句前后）
可以使用who或which——绝不用'that'
关系代词绝不可以省略
常与专有名词和独特事物搭配
绝不要在非限定性从句中使用'that'。'My mother, that is 60, loves gardening'是错误的。应该说：'My mother, who is 60, loves gardening.'
何时可以省略关系代词
在限定性从句中，你经常可以完全省略关系代词。这使句子更短更自然——母语者一直这样做。但你只能在特定情况下省略。
当代词是宾语时可以省略
The movie that I watched was boring.
The movie I watched was boring.
'I'是主语，'that'是宾语 → 可省略
The person who you met is my boss.
The person you met is my boss.
'you'是主语，'who'是宾语 → 可省略
The cake which she made was delicious.
The cake she made was delicious.
'she'是主语，'which'是宾语 → 可省略
当代词是主语时不可省略
The man who lives next door is friendly.
The man lives next door is friendly.
'who'是'lives'的主语 → 不可省略
The bus that goes to the airport is blue.
The bus goes to the airport is blue.
'that'是'goes'的主语 → 不可省略
快速测试：看关系代词后面跟什么。如果是动词，代词是主语 → 保留。如果是名词/代词（I、you、she、they...），代词是宾语 → 可以省略。
Where、When、Whose：其他关系词
除了who、which和that，英语还有三个其他关系词，用于特定目的。它们替代'in which'、'at which'或'of which'，使句子听起来更自然。
WHERE——用于地点
The restaurant where we had dinner was lovely.
I visited the town where I grew up.
'Where'替代'in which'或'at which'：The restaurant in which we had dinner → The restaurant where we had dinner.
WHEN——用于时间
I remember the day when we first met.
Summer is the season when most people travel.
'When'替代时间表达中的'in which'或'at which'：The day on which we met → The day when we met.
WHOSE——用于所有关系
The woman whose car was stolen called the police.
I have a friend whose brother is a pilot.
'Whose'替代所有格代词（his、her、its、their）。对人和物都适用：The house whose roof was damaged.
在非正式口语中，'when'和'where'有时可以用'that'替代或省略：'The day (that) we met.' 'The place (that/where) I work.' 但'whose'永远不能替代或省略。
「Which」指代整个句子
'which'的一个特殊用法让很多学习者困惑：它可以指代前面整个从句或想法，而不仅仅是一个特定名词。这总是带逗号的非限定性从句。
当'which'指代整个句子时，它评论的是整个情况——不是某个特定名词。这在口语和书面英语中都非常常见。
He passed all his exams, which surprised everyone.
'Which'指的是他通过考试这个事实——不是'exams'。
She arrived late, which annoyed her boss.
'Which'指的是她迟到这个事实。
The company raised prices, which led to fewer customers.
'Which'指的是涨价这整个行为。
He didn't apologize, which made things worse.
'Which'指的是不道歉这整个情况。
这里只能使用'which'——绝不能用'that'。'He passed his exams, that surprised everyone'是错误的。而且在这种结构中，'which'前面必须加逗号。
That vs Which：美式与英式的争论
英语语法中最有争议的问题之一是何时使用'that'与'which'。答案取决于你遵循的是美式还是英式惯例。
美式英语（严格规则）
限定性从句：使用'that'（首选）——The car that I bought...
非限定性从句：使用'which'（必须）——My car, which I bought last year,...
'That'和'which'不可互换
大多数美式风格指南（AP、Chicago）强制执行这一区别
英式英语（灵活）
限定性从句：'that'或'which'——都可以——The car that/which I bought...
非限定性从句：只用'which'——My car, which I bought last year,...
'Which'在限定性从句中使用更自由
学术和正式写作通常在限定性从句中使用'which'
所有人都同意的规则：非限定性从句（有逗号）总是使用'which'，绝不用'that'。争论只关于限定性从句。
给学习者的建议：遵循美式规则。限定性从句用'that'，非限定性从句用'which'。这更清晰，永远不会错，还能帮你看清两种从句类型的区别。
学习者在关系从句中常犯的错误
这些是学习者英语中最常出现的错误。大多数来自母语的直接翻译或混淆限定性和非限定性从句。
在非限定性从句中使用'that'
My mother, that is a teacher, lives in London.
My mother, who is a teacher, lives in London.
非限定性从句（有逗号）绝不使用'that'。
在关系代词后面加代词
The book that I read it was interesting.
The book that I read was interesting.
'That'已经替代了'it'。你不需要两个都用。
对物使用'who'
The car who broke down was old.
The car that/which broke down was old.
'Who'只用于人。对物使用'that'或'which'。
非限定性从句缺少逗号
London which is the capital of England is very expensive.
London, which is the capital of England, is very expensive.
非限定性从句必须有逗号。没有逗号，意思会改变或句子就是错的。
代词是主语时省略
The woman lives next door is friendly.
The woman who lives next door is friendly.
只有当代词是宾语时才能省略，主语时不行。
用'what'代替'that/which'
The thing what I like most is the music.
The thing that I like most is the music.
在标准英语中，'what'绝不是关系代词。使用'that'或'which'。
构建复杂句子：分步练习
现在让我们练习使用关系从句将简单句合并成复杂句。对每一对句子按三步法操作。
3步法
第1步：找出两个句子中的共同名词
第2步：用who/which/that替换第二个句子中的名词
第3步：将关系从句放在共同名词的正后方
I have a friend. She is a pilot.
I have a friend who is a pilot.
共同名词：friend/she → 'who'（人，主语）
We visited a museum. It was closed on Mondays.
We visited a museum that/which was closed on Mondays.
共同名词：museum/it → 'that'或'which'（物，主语）
The man is my uncle. You saw him yesterday.
The man (who/that) you saw yesterday is my uncle.
共同名词：man/him → 'who/that'（人，宾语——可省略）
She bought a dress. The dress was on sale.
She bought a dress that/which was on sale.
共同名词：dress → 'that'或'which'（物，主语）
I work in a building. The building was built in 1920.
I work in a building that/which was built in 1920.
共同名词：building → 'that'或'which'（物，主语）
挑战：多重关系从句
The teacher who taught me English, which was my favorite subject, retired last year.
你可以在一个句子中使用多个关系从句——但不要过度。两个通常是上限，否则句子会变得难以理解。
如何用FlexiLingo掌握关系从句
关系从句出现在几乎每个超过五个词的英语句子中。内化它们的最好方法是大量接触真实英语——在语境中听和读数千次，直到模式变得自动化。
23+平台的互动字幕
用互动字幕观看YouTube、Netflix、TED Talks等。注意说话者如何自然地在真实对话中使用'the person who'、'the thing that'和'which means that'。
一键保存复杂句子
当你听到关系从句的精彩例子——如'The company that hired me, which is based in London, has offices worldwide'——保存完整句子连同音频上下文以供复习。
AI驱动的语法分析
FlexiLingo的NLP引擎识别你观看内容中的从句结构、关系代词和句子复杂度。实时查看详细的语法模式。
间隔重复复习
以最佳间隔复习保存的例子。反复听到正确的关系从句模式——'who lives'、'that I saw'、'which was built'——建立本能的准确性。
常见问题
who、which和that有什么区别？
'Who'用于人：'The woman who called.' 'Which'用于物：'The car which broke down.' 'That'在限定性从句中对人和物都适用：'The woman that called' / 'The car that broke down.' 在非限定性从句（有逗号）中，只允许'who'（人）和'which'（物）——绝不用'that'。
什么时候应该在关系从句中使用逗号？
当从句添加的附加信息可以去掉而不改变核心意思时使用逗号（非限定性）。当从句对识别名词是必要的时不使用逗号（限定性）。比较：'My brother, who is a doctor, lives in Paris'（额外信息，一个兄弟）vs 'My brother who is a doctor lives in Paris'（识别哪个兄弟——我有好几个）。
我能总是用'that'替换'who'和'which'吗？
只能在限定性从句（无逗号）中。'The man that I met'和'The book that I read'都正确。但在非限定性从句（有逗号）中，你必须使用'who'或'which'：'My mother, who is 60, lives in London'——不是'My mother, that is 60, lives in London.'
什么时候可以省略关系代词？
只能在限定性从句中当代词是宾语（不是主语）时省略。测试：看代词后面跟什么。如果是另一个主语（I、you、she、they...），可以省略。'The movie (that) I watched'——可以省略。'The man who lives here'——不能省略（who = 'lives'的主语）。
'the reason why'对还是'the reason that'对？
两个都对，都常用。'The reason why I left'和'The reason that I left'都很自然。你甚至可以两个都省略：'The reason I left.' 在正式写作中，一些风格指南偏好'the reason that'或单纯的'the reason'，但'the reason why'在所有语境中都完全标准。