Grammar Rule in 30 Seconds
Non-defining clauses add extra, non-essential information about a noun using commas and relative pronouns like 'who' or 'which'.
- Always use commas to separate the extra info from the main sentence: 'My brother, who lives in Paris, is a chef.'
- Never use the word 'that' in these clauses; stick to 'who', 'which', 'whose', or 'where'.
- The sentence must still make perfect sense if you remove the entire clause between the commas.
Overview
Non-Defining Relative Clauses，它们有一个非常严格、非常重要的性格特征：它们必须有逗号。如果你忘了逗号，这个句子基本上就会崩溃。把逗号想象成小提手，让你能把额外的信息从句子里提出来。如果你能把这些词删掉，而句子依然完美运行，那么你手里的就是一个非限定性从句。这是你在八卦邻居家的 17 只猫时，让自己听起来很高大上的终极方法。Non-defining relative clauses 本质上就是“额外送”的信息。它们会告诉你关于人、物或地方的更多细节，但对于识别你在说谁或什么并不是必不可少的。想象一下你在给朋友讲你姐姐。如果你只有一个姐姐，说 My sister, who lives in Tokyo, is coming to visit 使用的就是非限定性从句。你朋友已经知道你说的是哪个姐姐了，因为你只有一个！她在东京住这个事实只是群聊里的一个酷炫额外细节。但是，如果你有五个姐姐，需要指明是哪一个，那就要用完全不同的规则了。这些从句就是“顺便提一下”这种能量的王者。它们让你能在故事、Instagram 文案或职业邮件中织入复杂的细节，而不需要另起一句。记住：这些从句就像那个总是在吃早午餐时分享过头的朋友——挺有意思，但对剧情走向并不是绝对必要的。How This Grammar Works
Paris, which is the capital of France, is beautiful. 我们都知道巴黎是什么。加上“法国首都”这一句并不能帮我们识别这个城市，它只是增加了点风味。为了实现这一点，我们会使用关系代词，比如 who、which、where 和 whose。但这里有一个金科玉律：在非限定性从句中永远不能使用 that。这就像尝试用叉子喝汤——根本行不通，而且你看上去会很傻。你也不能省略代词。在其他句子里，你可能会说 'The book I read'，但在这里，你必须说 The book, which I finished last night, was boring. 你需要那个代词来充当额外信息的桥梁。这有点像夜店里的 VIP 区；它有明确的边界（逗号）和一份不包含 that 的宾客名单（代词）。
Formation Pattern
My mom、Netflix、London）。
who，物用 which，地点用 where，所属关系用 whose。
My laptop (1), (2) which (3) I bought only last month (4), (5) is already acting like it's 100 years old (6). 一旦掌握了“逗号三明治”技巧，它就像流水一样顺畅！
When To Use It
My former boss, who recently started her own company, is hiring. 或者 Instagram 文案：This sunset, which I caught just before the rain started, was magical. 这在描述地标的 旅行 Vlogs 中也非常完美：The Colosseum, where gladiators used to fight, is even bigger in person. 它也经常出现在 Netflix 字幕或新闻报道中，用以提供人物或事件的背景。基本上，每当你发现自己想说“顺便说一下”或“如你所知”时，non-defining relative clause 就是你最好的朋友。它让你的写作更流畅，防止你写出 50 个短小碎裂的句子。这就是听起来像机器人和听起来像个会讲故事的地道母语使用者之间的区别。此外，在 Zoom 上的面试中描述你之前的职位时，这也是展示你语法实力的好机会。
Common Mistakes
that。记住：that 仅用于必要的信息。你不能说 My dog, that is a pug, is sleeping. 必须是 My dog, which is a pug, is sleeping. （实际上，对于有名字的宠物，我们经常用 who，因为我们爱它们！）。另一个陷阱是尝试删除代词。虽然在其他类型的从句中你经常可以省掉 who 或 which，但在这里你必须保留它们。My car, I bought last year, is fast 简直是大失败。你需要那个 which。最后，别忘了第二个逗号！很多人用逗号开了头，却忘了收尾，让额外信息悬在半空中。这就像只关上一边的括号——感觉就是不对。这就像只穿了一只鞋就出门了；别人会注意到，而且场面会很尴尬。Contrast With Similar Patterns
The man who lives next door is a spy. 如果你删掉 who lives next door，你就是在说 The man is a spy. 哪个男人？没人知道！这里不用逗号。但在我们的非限定版本中：Mr. Smith, who lives next door, is a spy. 我们已经知道是史密斯先生了。'lives next door' 部分只是一个趣闻。使用“删除测试”——如果你能删除从句，而句子仍然通顺且能识别出同一个人/物，那就是非限定性的。另外，记住 that 规则：限定性从句热爱 that (The phone that I want is expensive)，但非限定性从句讨厌它。这种竞争关系比 Mac vs. PC 还要深。Quick FAQ
我可以用 whoever 或 whichever 吗？
并不行。那些是用于不同结构的。对于这种特定的“额外信息”从句，请坚持使用基础款：who、which、where 和 whose。
如果额外信息在句末怎么办？
简单！你只需要在代词前加一个逗号，最后加一个句号。像这样：I'm going to visit London, which is my favorite city.
对动物用 who 可以吗？
如果这只动物有名字，或者你觉得和它有情感连接，那就大胆用吧！如果只是“一只蜘蛛”或“那只鸟”，用 which 更保险。
这会让我的口语听起来太正式吗？
完全不会！这只会让你听起来谈吐不凡。即使在随意的短信中，使用一个简短的 which 从句也能让你的观点更清晰。
为什么我不能用 that？
说实话？这只是英语里那种“我说了算”的规则之一。语法学家很久以前就认定 that 仅用于必要信息，从那以后我们就一直被这规则困住了。尽情拥抱 which 吧！
Memory Trick
把逗号想象成 'The Handles'（提手）。就像篮子有两个提手让你能把它拎起来移走一样，非限定性从句有两个逗号，让你能拎起额外的信息并把它从句子里“提”出来。如果你在“拎”走篮子后，句子本身依然能完美立足，那么这些逗号就理应存在！
Relative Pronoun Selection
| Target | Pronoun | Example Clause |
|---|---|---|
|
People
|
who
|
, who lives next door,
|
|
Things/Animals
|
which
|
, which cost $50,
|
|
Possession
|
whose
|
, whose car was stolen,
|
|
Places
|
where
|
, where we met,
|
|
Time
|
when
|
, when the sun sets,
|
|
Whole Sentences
|
which
|
, which is why I'm late.
|
Meanings
A non-defining relative clause provides additional information about a person, thing, or place that is already clearly identified. It is not essential for the sentence to be understood.
Adding info about people
Using 'who' to provide biographical or situational details about a specific person.
“Mr. Smith, who is 70 years old, still goes jogging every morning.”
“My sister, who you met yesterday, is moving to Canada.”
Adding info about things
Using 'which' to describe an object or concept that has already been named.
“The Taj Mahal, which was built in the 17th century, is a UNESCO World Heritage site.”
“My new phone, which cost a fortune, is already broken.”
Possession with 'whose'
Adding extra info about who something belongs to.
“The neighbor, whose dog barks all night, is actually very nice.”
“The company, whose profits have doubled, is hiring new staff.”
Adding info about places
Using 'where' to give extra context about a location.
“Paris, where I spent my honeymoon, is beautiful in the spring.”
“The local park, where we used to play football, has been closed.”
Commenting on a whole sentence
Using 'which' after a comma to comment on the entire preceding clause.
“He arrived late, which was very rude.”
“She passed the exam, which surprised everyone.”
Reference Table
| 关系代词 | 指代对象 | 非限制性例子 (额外信息) | 限定性例子 (必要信息) |
|---|---|---|---|
|
who
|
人
|
My sister, who lives in Canada, is visiting soon.
|
The student who aced the exam got a scholarship.
|
|
whom
|
人 (宾语/正式)
|
The CEO, whom I met yesterday, was very approachable.
|
The person whom you spoke to earlier has left.
|
|
whose
|
所属关系 (人或物)
|
My dog, whose name is Loki, loves chasing squirrels.
|
I know a guy whose car is electric.
|
|
which
|
事物/观点
|
The new café, which has amazing pastries, is always busy.
|
The book which I borrowed from you is fantastic.
|
|
where
|
地点
|
London, where I grew up, is a vibrant city.
|
The park where we first met is beautiful.
|
|
when
|
时间
|
Next Tuesday, when the new movie comes out, I'm going.
|
I remember the day when we graduated.
|
正式程度
My brother, who resides in London, is a medical practitioner. (Family description)
My brother, who lives in London, is a doctor. (Family description)
My brother, who's living in London now, is a doctor. (Family description)
My bro, who's up in London, is a doc. (Family description)
非限制性从句：“额外信息”地图
核心特征
- 逗号 Always use commas!
- 可移除性 Sentence still makes sense without it
- 禁用 That Never use 'that' here
关系代词
- Who For people
- Which For things/ideas
- Whose For possession
- Where For places
- When For times
限定性 vs 非限定性：一眼看穿区别！
如何选择定语从句：快速指南
该信息对于识别名词是否必不可少？
从句是指代人吗？
从句是指代物或观点吗？
从句表示所属关系吗？
非限制性从句专用代词
指代人
- • who
- • whom (正式)
- • whose
指代物/观点
- • which
- • whose
指代地点
- • where
指代时间
- • when
按水平分级的例句
My dad, who is a teacher, is nice.
London, which is big, is in England.
My car, which is red, is fast.
Sarah, who is my friend, is here.
My house, which has three bedrooms, is old.
The teacher, who is very kind, helped me.
Paris, where the Eiffel Tower is, is beautiful.
My brother, whose name is Tom, is a doctor.
The new shopping mall, which opened last week, is huge.
My boss, who travels a lot, is in New York now.
The movie, which we saw yesterday, was quite boring.
Italy, where my parents were born, is a sunny country.
The company, which was founded in 1920, is going bankrupt.
He forgot my birthday, which made me very angry.
The scientist, whose research is famous, won a prize.
The hotel, where we stayed for two weeks, was excellent.
The proposal, which the board rejected yesterday, was very detailed.
The city, the history of which is fascinating, attracts many tourists.
The witness, who had been silent until then, finally spoke.
The project, which I have been working on for months, is finally finished.
The Prime Minister, whose popularity has waned recently, faces a challenge.
The cathedral, the construction of which took 200 years, is a masterpiece.
He was unable to attend, which, given the circumstances, was understandable.
The theory, which has been widely criticized, remains influential.
容易混淆
Learners don't know when to use commas and when not to.
Learners want to use 'that' in all relative clauses.
常见错误
My brother that is tall is here.
My brother, who is tall, is here.
London which is big is in England.
London, which is big, is in England.
My car, that I bought last year, is broken.
My car, which I bought last year, is broken.
The city where I was born in is beautiful.
The city, where I was born, is beautiful.
句型
[Proper Name], who ___, is ___.
[Specific Object], which ___, was ___.
[Clause], which ___.
Real World Usage
The President, who is 78, arrived today.
My cat, which is literally a demon, just broke my vase.
My last project, which I led for six months, was a success.
The hotel, where we stayed last summer, has closed down.
I saw Sarah, who says hi btw.
This theory, which was developed in 1920, is still used.
逗号是你的好帮手
My house, which was built in 1920, needs repairs.
这里严禁使用 'That'！
The cake, which she made, was delicious.
读出节奏感
My boss, who is usually strict, smiled today.
让你的故事更生动
My neighbor, whose dog barks all night, is actually very nice.
Smart Tips
Always use commas. Since the name already identifies them, any extra info is by definition 'non-defining'.
Use ', which' at the end of your sentence to add a comment.
Make sure the place is a setting. If you are describing the place as an object, use 'which'.
Combine them! Use a non-defining clause to turn two boring sentences into one interesting one.
发音
The Comma Pause
In speech, there is a slight pause and a drop in pitch at each comma.
Parenthetical Dip
The car, ↘ which was red, ↗ is mine.
The lower pitch indicates the information is secondary.
记住它
记忆技巧
Commas are like handles on a suitcase: they hold the extra stuff you're carrying.
视觉联想
Imagine a 'comma sandwich'. The two commas are the bread, and the extra information is the delicious filling. Without the bread, the filling falls out and makes a mess!
Rhyme
If the info is just a plus, use a comma and don't make a fuss.
Story
A detective is describing a suspect. 'The man is tall.' (Boring). 'The man, who was wearing a red hat, is tall.' The red hat is the extra clue that helps the story but isn't the main point.
Word Web
挑战
Look at three objects in your room. Write one sentence for each using a non-defining clause (e.g., 'My laptop, which I bought last year, is on the desk.').
文化笔记
British speakers are often very strict about using 'which' for non-defining clauses and 'that' for defining ones.
News outlets like the BBC or NYT use these clauses to provide titles and ages efficiently.
Non-defining clauses are used to cite sources or provide definitions without stopping the flow.
Relative clauses in English evolved from demonstrative pronouns in Old English.
对话开场白
Tell me about your best friend, who I haven't met yet.
What is your favorite city, which you've visited recently?
Tell me about your first car, which you probably don't have anymore.
日记主题
常见错误
Test Yourself
My best friend ___ is a brilliant artist, just had her first exhibition.
Find and fix the mistake:
The new cafe that has a rooftop terrace is very popular.
Arrange the words in the correct order:
All words placed
Click words above to build the sentence
Score: /3
练习题
8 exercisesWhich sentence is punctuated correctly?
Paris, ___ is the capital of France, is beautiful.
Find and fix the mistake:
My car, that I bought last week, is already broken.
Mr. Jones is our neighbor. He is 80 years old.
You can use 'that' in a non-defining relative clause.
The book, which I finished yesterday, was great.
Match the following:
my / which / is / old / car / , / red / , / is
Score: /8
Practice Bank
12 exercisesMy phone ___ I bought last year, is already acting up.
My boss, that is usually very strict, was surprisingly lenient today.
选择正确的句子：
翻译成英语：'我的姐姐住在马德里，她要来拜访我。'
将单词排序：
将主语与正确的非限制性从句配对：
The concert, ___ tickets sold out in minutes, was spectacular.
The movie, I watched last night, was incredibly boring.
选择正确的句子：
翻译成英语：'周一我有期末考试，到时我会压力很大。'
将单词排序：
将主句开头与合适的非限制性从句结尾配对：
Score: /12
常见问题 (8)
No, never. In English, 'that' is strictly for defining clauses. If you have commas, you must use 'who' or 'which'.
It creates a 'run-on' feeling and can confuse the reader about where the main verb of the sentence is.
Yes, in very formal writing, 'whom' is used if the person is the object of the clause: 'My boss, whom I respect, is leaving.'
Yes! This is called a sentential relative clause. Example: 'He was late, which was annoying.'
You only need the first comma. Example: 'I live in London, which is a big city.'
Try the 'Deletion Test'. If you remove it and the sentence still identifies the noun clearly, it's extra (non-defining).
Yes, for places. 'My school, where I studied for 5 years, is closing.'
It is very common in both, but you will see much longer and more complex ones in formal writing.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Oraciones de relativo explicativas
Spanish uses 'que' for both; English requires 'which/who' and forbids 'that'.
Relativsätze
German always uses commas; English only uses them for non-defining clauses.
Propositions subordonnées relatives
French 'que' is used for objects, while English uses 'which' or 'who(m)'.
連体修飾節 (Rentai shuushikusetsu)
Japanese has no relative pronouns and the clause precedes the noun.
الصلة (Al-Sila)
Arabic relative pronouns change based on gender and number, and the definite/indefinite distinction is crucial.
的 (de) structure
Chinese puts all descriptions before the noun using 'de'.
Learning Path
Prerequisites
Learn These First
Continue With
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