Grammar Rule in 30 Seconds
Defining relative clauses give essential information to identify exactly which person or thing you are talking about.
- Use 'who' or 'that' for people (e.g., The man who called).
- Use 'which' or 'that' for things (e.g., The car that I bought).
- Never use commas before or after a defining relative clause.
Overview
How This Grammar Works
that I rented in Ibiza）」と言うことができます。どちらもどの車かを教えてくれますが、関係節の方が詳細を説明する余裕があります。メインの文に、名詞に「接着」させた関係節をくっつけます。whoとthatは人のために。whichとthatはものや動物のために。whoseは所有（携帯が鳴っている人など）のために。whereは場所のために。
that I drank）」は、単に「The coffee I drank」とすることができます。しかし、代名詞が「主語」である場合は、残さなければなりません。「The girl lives next door is nice」とは言えません。「who」が必要です！ジムの会員権のようなものです。たまにはサボる日があってもいいですが、重いリフティング（大事な場面）では出席しなければなりません。
Formation Pattern
who / that | 私にメールをくれた（who）男の人。 | 人には who がより一般的です。
which / that | 私がハマっている（that）番組。 | カジュアルな会話では that が非常に一般的です。
where | 私たちが出会った（where）カフェ。 | 'at which' や 'in which' の代わり。
whose | 猫が有名な（whose）女の子。 | 人にもものにも使えます。
that） | 私が注文したピザ。 | 目的語なら that を飛ばせます。
When To Use It
that）好きそうな映画」のようなカテゴリーでいっぱいです。あるいはAmazonのカート：「最近チェックした（that）商品」。具体的に説明する必要があるときに使います。- SNS：「あのイタい動画を投稿した（
who）インフルエンサー」 - 旅行：「ベルリンで私たちが泊まった（
where）ホステルは朝食が無料だった！」 - 仕事：「リモートワークができる（
that）会社を探しています」
that）アプリだよ」。ここで「アプリ」を定義しています。単に「アプリだよ」と言うだけでは、おばあちゃんは困ったままでしょうし、あなたは永遠に彼女のテックサポートをすることになるでしょう。
Common Mistakes
who を使ってしまうことです。「The laptop who I bought」とは言わないでください。ノートパソコンには（まだ）感情はありません。which か that を使いましょう。who she lives next door」とよく言ってしまいがちです。すでに who が主語としてあります！ she は必要ありません。サングラスを2つかけているようなものです。かっこよく見えるかもしれませんが、冗長です。whose を忘れないでください。「The man that his car was stolen」と言うのは避け、「The man whose car was stolen」を使いましょう。その方がスムーズで、プロっぽく聞こえます。Contrast With Similar Patterns
- 制限的：「勉強した（
who）学生はテストに合格した」（勉強した人だけ！他の人は？たぶんFortniteをやってたんでしょうね。） - 非制限的：「学生たちは、一生懸命勉強したので（
who）、テストに合格した」（学生全員が勉強して、ちなみに全員合格した。）
that と which も紛らわしいかもしれません。アメリカ英語では、制限的節にはほぼ常に that を使い、非制限的節には which を使います。イギリス英語ではもう少し柔軟ですが、カジュアルな会話の制限的節ではやはり that が王様です。where vs which です。「私が住んでいる（where）街」vs「私が訪れた（which）街」。where を使うなら、'in' のような前置詞は不要です。which を使うなら、通常必要です：「The city which I live in」。where を使うのはスーパーの「特急レジ」のようなもので、ただただ早いです。Quick FAQ
人に対して常に that を使ってもいいですか？
はい、制限的節では、人に対して that を使っても大丈夫です。でも who の方が少し自然で丁寧な響きになります。
who/which/that を省略できるのはいつですか？
目的語であるときだけです。「私が見た（that）人」。主語である場合は残してください！「私を見た（who）人」。
whom はまだ使われていますか？
主にフォーマルなメールや、かなり古い本などで使われます。2026年現在、ほぼすべての場面で who で全く問題ありません。
where の前にカンマは必要ですか？
制限的節では不要です！「私が働いている（where）場所は駅の近くです」。カンマは禁止です。
関係節が2つある場合はどうなりますか？
重ねることができます！「Googleで働いている（who）、私が出会った（who）男の人」。少し言いづらいですが、文法的にはOKです。
Relative Pronoun Selection
| Target | Subject Form | Object Form | Possessive Form |
|---|---|---|---|
|
People
|
who / that
|
who / whom / that / (omitted)
|
whose
|
|
Things
|
which / that
|
which / that / (omitted)
|
whose / of which
|
|
Places
|
which / that
|
where
|
n/a
|
|
Times
|
that
|
when
|
n/a
|
Meanings
A defining relative clause provides information that is necessary to identify the noun it follows. Without this clause, the sentence would be incomplete or the meaning would change significantly.
Identifying People
Using 'who' or 'that' to specify which person is being discussed.
“The woman who lives next door is a doctor.”
“I know a girl that speaks five languages.”
Identifying Things
Using 'which' or 'that' to specify which object or concept is being discussed.
“The book which I borrowed is excellent.”
“This is the phone that has the best camera.”
Possession
Using 'whose' to show who something belongs to within the identifying clause.
“The boy whose father is a pilot is my friend.”
“I met a woman whose car had broken down.”
Reference Table
| 関係代名詞 | 指すもの | 使い方 | 例 |
|---|---|---|---|
|
who
|
人
|
主語または目的語
|
`The friend who called.`
|
|
which
|
物 / 動物
|
主語または目的語
|
`The phone which rang.`
|
|
that
|
人 / 物 / 動物
|
主語または目的語
|
`The idea that succeeded.`
|
フォーマル度スペクトル
The gentleman whom I encountered this morning. (social_interaction)
The man who I met this morning. (social_interaction)
The guy I met this morning. (social_interaction)
The dude I linked with earlier. (social_interaction)
限定関係代名詞：基本
代名詞
- who 人用
- which 物・動物用
- that 人・物用（カジュアル）
機能
- Identify 「どれ？」を特定する
- Clarify 曖昧さを防ぐ
構造
- No commas 意味に不可欠な部分
- Follows noun 修飾する名詞の直後
限定節におけるWho vs. Which vs. Thatの比較
関係代名詞の選び方（限定節）
その情報はその名詞を特定するために不可欠ですか？
その名詞は人ですか？
その名詞は物または動物ですか？
限定節が役立つ場面
人を特定する
- • 私にお金を貸してくれた友達。
- • 私のエッセイを採点してくれた先生。
- • オスカーを獲得した俳優。
物を特定する
- • 私が読み終えた本。
- • 大きな音で鳴った電話。
- • みんなが観た映画。
文脈を明確にする
- • オーツミルク入りのコーヒー。
- • 歩数を記録するアプリ。
- • バズったミーム。
レベル別の例文
The man who is happy is my dad.
The man who is happy is my dad.
The dog which is big is mine.
The dog which is big is mine.
I like the girl who is nice.
I like the girl who is nice.
This is the house which is blue.
This is the house which is blue.
The phone that I have is new.
The phone that I have is new.
The people that live here are kind.
The people that live here are kind.
Where is the cake that I bought?
Where is the cake that I bought?
I saw the movie that you liked.
I saw the movie that you liked.
The woman whose car broke down is waiting.
The woman whose car broke down is waiting.
The hotel where we stayed was cheap.
The hotel where we stayed was cheap.
The reason why I called is important.
The reason why I called is important.
Is that the man you were talking about?
Is that the man you were talking about?
The candidate whom we interviewed yesterday was impressive.
The candidate whom we interviewed yesterday was impressive.
The city in which he was born is very small.
The city in which he was born is very small.
The students failing the test will need to retake it.
The students failing the test will need to retake it.
It was the atmosphere that made the restaurant special.
It was the atmosphere that made the restaurant special.
The speed at which the virus spread was alarming.
The speed at which the virus spread was alarming.
Any person found trespassing will be prosecuted.
Any person found trespassing will be prosecuted.
The extent to which he went to help was amazing.
The extent to which he went to help was amazing.
He is a man for whom I have great respect.
He is a man for whom I have great respect.
The manner in which the data was manipulated suggests fraud.
The manner in which the data was manipulated suggests fraud.
Such was the intensity with which she studied that she fell ill.
Such was the intensity with which she studied that she fell ill.
The person to whom the letter was addressed has moved.
The person to whom the letter was addressed has moved.
The criteria by which we judge art are subjective.
The criteria by which we judge art are subjective.
間違えやすい
Learners often use commas in defining clauses or use 'that' in non-defining clauses.
Using 'what' to mean 'the thing that'.
Mixing up the person with their possessions.
よくある間違い
The man what lives here.
The man who lives here.
The car who I like.
The car that I like.
The boy he is my friend.
The boy who is my friend.
I like the book is red.
I like the book that is red.
The man, who is tall, is my uncle.
The man who is tall is my uncle.
The girl who she called me.
The girl who called me.
The house that I live.
The house where I live.
The man whose his car is red.
The man whose car is red.
The reason because I came.
The reason why I came.
The book I read it was good.
The book I read was good.
The person that I gave the book.
The person to whom I gave the book.
文型パターン
The ___ who ___ is ___.
I'm looking for a ___ that ___.
That is the ___ where ___.
He is the kind of person whose ___ is always ___.
Real World Usage
I am looking for a role that allows me to use my coding skills.
Show me the laptops that are under $500.
I want to meet someone who loves hiking and travel.
The suspect is a man who was wearing a blue hoodie.
Did you see the video I sent you?
Take the bus that stops in front of the library.
「絶対に必要な情報」だと考えてね💡
限定節には「カンマはつけない」よ⚠️
迷ったら「that」を使ってみよう🎯
who と which のどちらを使うか迷ったら、カジュアルな場面では that が人にも物にもほとんどの場合安全で自然な選択肢です。あなたの「万能カード」だと思ってくださいね！「The person that called.」「whom」は「とてもフォーマル」だよ🌍
whom は文法的には who の目的格として正しいですが、日常会話ではほとんど使われません。主にとてもフォーマルな文章やスピーチで出会うでしょう。毎日使うことについては、あまり心配しなくて大丈夫ですよ。「The project manager with whom I discussed the issue was very helpful.」Smart Tips
You can probably omit the relative pronoun entirely to sound more like a native speaker.
Avoid using 'that' for people; use 'who' or 'whom' instead to maintain a professional tone.
Try removing the clause. If the sentence becomes confusing or 'The [Noun]' doesn't refer to anyone specific anymore, don't use commas.
Remember that 'whose' replaces 'his/her/their' + the noun. Don't keep the possessive adjective!
発音
Relative Pronoun Reduction
In fast speech, 'that' is often pronounced with a schwa /ðət/.
Stress on the Noun
The stress usually falls on the noun being defined, not the relative pronoun.
Continuous Flow
The girl who lives next door ↗ is a doctor.
There is no pause between the noun and the defining clause.
暗記しよう
記憶術
WHO is for humans, WHICH is for things, and THAT is the friend that fits both strings.
視覚的連想
Imagine a giant magnifying glass hovering over a crowd of people. The glass highlights one person wearing a 'WHO' t-shirt. This represents how the clause 'defines' or 'zooms in' on one specific person.
Rhyme
If the info is a must, no commas you shall trust.
Story
A detective is looking for a thief. He says, 'I need the man WHO has the red bag.' There are ten men, but only one has the red bag. The 'who' clause is the detective's tool to find the right person.
Word Web
チャレンジ
Look around your room. Pick three objects and describe them using 'that' or 'which' (e.g., 'The lamp that is on my desk is black').
文化メモ
American English speakers strongly prefer 'that' over 'which' for defining clauses. Using 'which' can sometimes sound overly formal or even British to American ears.
British English is more accepting of 'which' in defining clauses, though 'that' is still very common in speech.
In formal academic papers, 'whom' is still expected when the person is the object of the clause, whereas it has almost disappeared from spoken English.
Relative pronouns in English evolved from interrogative pronouns (who/which) and demonstrative pronouns (that).
会話のきっかけ
Tell me about a person who has influenced your life.
What is a gadget that you can't live without?
Describe the kind of house where you would like to live.
Think of a movie that made you cry. Why was it so sad?
日記のテーマ
よくある間違い
Test Yourself
The person ___ helps me with tech is very patient.
Find and fix the mistake:
The film, that I saw, was fantastic.
Choose the correct sentence:
El restaurante que tiene la mejor pizza siempre está lleno.
Answer starts with: ["T...
Arrange the words in the correct order:
All words placed
Click words above to build the sentence
Score: /5
練習問題
8 exercisesThe woman ___ lives next door is a famous singer.
Which sentence is punctuated correctly?
Find and fix the mistake:
The man who he called me is my boss.
I have a friend. Her father is a doctor.
You can use 'that' instead of 'who' for people in defining clauses.
A: Which book do you want? B: I want the one ___ is on the top shelf.
The movie that we saw last night was great.
1. The person... 2. The car... 3. The girl... 4. The house...
Score: /8
Practice Bank
13 exercisesI read the article ___ was recommended by my professor.
The architect ___ designed this building won an award.
Is this the laptop ___ you want to buy?
The doctor which I saw was very kind.
The book, that was on the table, is mine.
Which sentence is correct?
Which sentence is correct?
El coche que está aparcado allí es nuevo.
No me gusta la gente que se queja mucho.
Arrange these words into a sentence:
Put the words in the correct order:
Match the relative pronouns with their usual referents:
Match the sentence parts:
Score: /13
よくある質問 (8)
You can leave it out only if it is the **object** of the clause. For example, in 'The man [that] I saw', 'I' is the subject and 'that' is the object, so you can omit it. In 'The man who called', 'who' is the subject, so you must keep it.
Neither is 'better', but 'who' is more common in formal writing, while 'that' is very common in everyday speech.
No, 'which' is strictly for things and animals. For people, use 'who' or 'that'.
Commas in English indicate that the information is 'extra'. In defining clauses, the information is essential to identify the noun, so we don't use commas.
'Who' is for subjects and 'whom' is for objects. However, 'whom' is very formal and rarely used in spoken English today.
Yes! You can say 'The tree whose leaves are falling' instead of the more clunky 'The tree of which the leaves are falling'.
In American English, 'that' is preferred for defining clauses. In British English, both 'that' and 'which' are used frequently.
Yes, 'where' is much more natural in conversation. 'The house where I live' is better than 'The house in which I live'.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
que
English has different pronouns for people vs. things, whereas Spanish often uses 'que' for both.
qui / que
French never omits the relative pronoun, while English often does.
der / die / das
German relative clauses always require commas, even if they are defining.
None (Adnominal clause)
Japanese uses word order instead of pronouns like 'who' or 'which'.
al-ladhi (الذي)
English does not use resumptive pronouns (e.g., we don't say 'the man who I saw him').
de (的)
The relative clause precedes the noun in Chinese but follows it in English.
Learning Path
Prerequisites
Continue With
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関連動画
09:00 The Deadliest Virus on Earth
07:46 You Are Not Where You Think You Are
06:59 No, honey can’t cure your allergies
Relative Clauses (Defining & Non-Defining) | EasyTeaching
EasyTeaching
Defining and Non-Defining Relative Clauses - English Grammar Lesson
Oxford English Now
Reduced Relative Clauses - Defining and Non- Defining Relative Clauses - Advanced Grammar Lesson
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Related Grammar Rules
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