Grammar Rule in 30 Seconds
Reduced relative clauses allow you to remove the relative pronoun and 'be' verb to create concise, professional-sounding sentences.
- Active: Remove 'who/which/that' + 'be' and use the -ing form. Example: 'The man (who is) sitting there.'
- Passive: Remove 'who/which/that' + 'be' and use the past participle. Example: 'The car (which was) stolen yesterday.'
- Prepositional: Remove 'who/which/that' + 'be' before a preposition. Example: 'The book (that is) on the table.'
Overview
who, which, that）を使いこなせるようになった皆さんが、次に取り組むべき課題は、いかにして「冗長さを削ぎ落とし、自然でリズムの良い英文を作るか」という点にあります。そのための強力な武器となるのが、今回解説する「関係詞節の簡略化（Reduced Relative Clauses）」です。who is running や which was written といったフルサイズの形容詞節を、意味を損なうことなく running や written という短い形容詞句に圧縮するテクニックです。この文法の習得は、単に「文を短くする」という以上の意味を持ちます。それは、英語特有の「言語の経済性（Linguistic Economy）」を理解し、ネイティブスピーカーが好む「簡潔で力強い表現」を身につけることを意味します。The report that was submitted by the team is comprehensive. と書くよりも、The report submitted by the team is comprehensive. と書く方が、よりプロフェッショナルで、情報の密度が高い印象を与えます。日本語でも「チームによって提出されたところの報告書」と言うより「チーム提出の報告書」と言う方がスッキリするのと似ていますが、英語ではこの「削ぎ落とし」が文法的なルールに基づいて行われます。本稿では、この魔法のようなテクニックを、日本人が躓きやすいポイントを交えながら徹底的に解説していきます。- 「あそこで走っている男性」
- 「フランス語で書かれた手紙」
be 動詞が続く場合に、そのセットを丸ごと削除することができます。-ing）」や「過去分詞（-ed）」が、時制（現在・過去）に縛られない「非限定（Non-finite）」の形になるという点です。文全体の時制はメインの動詞が決定するため、簡略化された部分はどの時制の文にもフィットします。ing と ed を使い分けることで、同様のニュアンスを名詞の直後に配置できるのです。-ing)be + -ing）である場合や、習慣的な動作を表す場合がこれに当たります。- 公式:
名詞 + [who/which/that + be] + Verb-ing→名詞 + Verb-ing
The engineers who are designing the bridge are skilled.- →
The engineers designing the bridge are skilled.
The road that leads to the coast is closed.- →
The road leading to the coast is closed.
-ed / 不規則形)be + 過去分詞）である必要があります。- 公式:
名詞 + [who/which/that + be] + Past Participle→名詞 + Past Participle
The theories that were discussed in class are complex.- →
The theories discussed in class are complex.
The building which was built in 1920 is a landmark.- →
The building built in 1920 is a landmark.
be 動詞 ＋ 形容詞句・前置詞句の簡略化be 動詞の後に、形容詞の塊や前置詞の塊が続く場合も、セットで省略可能です。- 公式:
名詞 + [who/which/that + be] + 句→名詞 + 句
- 前置詞句:
The box that is on the table is heavy. - →
The box on the table is heavy. - 形容詞句:
He is a person who is capable of great things. - →
He is a person capable of great things.
The author whom I admire...（私が尊敬する著者は…）
The author admiring I... とすることは不可能です。なぜなら、著者が「尊敬している」のではなく、私が著者を「尊敬している」からです。ただし、目的格の関係代名詞そのものを省略して The author I admire... とすることは可能です（これは接触節と呼ばれ、別のルールです）。- 情報の密度を高めたいとき（アカデミック・ビジネス）
The data collected from the survey shows a clear trend.（調査から収集されたデータは、明確な傾向を示している。）
- 文のリズム（フロー）を改善したいとき
The manager responsible for the project launching next week called a meeting.（来週ローンチするプロジェクトを担当しているマネージャーが、会議を招集した。）
who is responsible と which is launching を両方使うよりも、ずっとスマートです。- 日常会話でスピーディーに描写したいとき
who is と言う手間を省きます。Who's that guy talking to Sarah?（サラと話しているあの男の人は誰？）I'll take the pizza topped with extra cheese.（エクストラチーズが乗ったピザにするよ。）
- 名詞の性質を強調したいとき
The skills required for this job are extensive.（この仕事に求められるスキルは多岐にわたる。）
- 誤:
The students boring in the class fell asleep. - 正:
The students bored in the class fell asleep. - 理由: 学生は「退屈させている（能動）」のではなく、授業によって「退屈させられている（受動）」状態だからです。
happen や arrive は自動詞であり、受動態が存在しません。- 誤:
The accident happened yesterday was tragic. - 正:
The accident that happened yesterday was tragic. - 注意:
happenedだけでは「昨日起きた事故」にはなりません。自動詞の場合、進行形的な意味が含まれない限り、単純な分詞への簡略化が難しい場合があります。この場合は関係代名詞を残すか、The accident occurring yesterday（やや不自然）とするよりは、フルサイズの方が安全です。
- 誤:
The letter wrote by him... - 正:
The letter written by him... - 解説: 日本語では「書いた手紙」と過去形のように言いますが、英語で名詞を後ろから修飾する際は、必ず「過去分詞（
written）」である必要があります。built,taken,chosen,heldなどの不規則変化は、就活（Job hunting）のレジュメやビジネス文書で頻出するため、完璧に覚えておく必要があります。
The man who is standing there is my boss. | 丁寧、説明的、あるいは強調したい時に使う。 |The man standing there is my boss. | 自然、簡潔。日常会話からビジネスまで主流。 |Mr. Tanaka, the CEO of our company, is here. | who is を省略している点では同じだが、名詞で名詞を説明する。 |The book I bought yesterday is good. | 目的格の関係代名詞を省略。分詞は使わない。 |The man, (who is) an expert in AI, gave a speech. のように、名詞句で説明する場合は「同格」と呼ばれますが、根底にある「不要な who is を省く」というロジックは共通しています。これらを使い分けることで、あなたの英語は格段に「大人な表現」へと進化します。be 動詞が続く（あるいは進行形・受動態である）場合に限られます。また、who works のように be 動詞がない一般動詞の場合、working と簡略化できることもありますが、意味が変わってしまう場合（習慣 vs 一時的動作）があるため、B2レベルではまず be 動詞を含むパターンの習得を優先しましょう。being を残す必要はありますか？The report being submitted... と言う場合、それは「（今まさに）提出されている最中の報告書」という進行のニュアンスが非常に強くなります。通常、単に「提出された報告書」と言いたい場合は、being は不要で、過去分詞のみで十分です。-ing にして良いですか？knowing とは言わず known を使ったり、そもそも簡略化せずに who knows としたりします。動詞の性質（状態動詞か動作動詞か）を考えることが、ミスを防ぐ鍵となります。who is や which was を削ってみることから始めてみてください。一歩ずつ、より自然で流暢な英語を目指して頑張りましょう（頑張る spirit で！）How to Reduce Different Verb Types
| Original Verb Type | Full Relative Clause | Reduced Relative Clause | Rule |
|---|---|---|---|
|
Present Continuous
|
The man who is working
|
The man working
|
Drop 'who is'
|
|
Past Continuous
|
The girl who was singing
|
The girl singing
|
Drop 'who was'
|
|
Simple Present
|
The path that leads home
|
The path leading home
|
Change verb to -ing
|
|
Simple Past
|
The person who saw it
|
The person seeing it
|
Change verb to -ing
|
|
Passive Voice
|
The book which was written
|
The book written
|
Drop 'which was'
|
|
Prepositional
|
The cat that is on the mat
|
The cat on the mat
|
Drop 'that is'
|
Meanings
A reduced relative clause is a relative clause that is not marked by an explicit relative pronoun (like who, which, or that) or a finite verb. It functions as an adjective to modify a noun, making the sentence more compact.
Active Voice Reduction
Used when the noun is performing the action. The relative pronoun and 'be' verb are removed, leaving the present participle (-ing).
“People living in glass houses shouldn't throw stones.”
“The woman leading the parade is my aunt.”
Passive Voice Reduction
Used when the noun is receiving the action. The relative pronoun and 'be' verb are removed, leaving the past participle (-ed/irregular).
“The house built in 1920 is being renovated.”
“Items purchased on sale cannot be returned.”
Prepositional Phrase Reduction
Used when the relative clause contains a prepositional phrase. Only the pronoun and 'be' verb are deleted.
“The keys on the counter are mine.”
“The man in the suit is the CEO.”
Adjective Phrase Reduction
Used when the relative clause consists of an adjective or adjective phrase. Usually occurs with adjectives that follow the noun.
“The person responsible for the mess should clean it.”
“We need a room large enough for fifty people.”
Reference Table
| 元の節のタイプ | フルセンテンスの例 | 省略形の例 | 省略の理由 |
|---|---|---|---|
|
能動態 (Active)
|
The student `who is talking` is my brother.
|
The student `talking` is my brother.
|
主語（学生）が動作を「している」ため。
|
|
受動態 (Passive)
|
The book `which was written` by her is great.
|
The book `written` by her is great.
|
主語（本）が動作を「されている」ため。
|
|
能動態 (Active)
|
The birds `that are singing` woke me up.
|
The birds `singing` woke me up.
|
主語（鳥）が鳴く動作を「している」ため。
|
|
受動態 (Passive)
|
The food `that was prepared` for the party was delicious.
|
The food `prepared` for the party was delicious.
|
主語（料理）が「準備された」ため。
|
|
能動態 (Active)
|
The person `who is waiting` for the bus is late.
|
The person `waiting` for the bus is late.
|
主語（人）が「待っている」状態のため。
|
|
受動態 (Passive)
|
The products `that are sold` here are local.
|
The products `sold` here are local.
|
主語（製品）が「売られている」ため。
|
フォーマル度スペクトル
The gentleman wearing the azure shirt is my superior. (Workplace)
The man wearing the blue shirt is my boss. (Workplace)
The guy in the blue shirt is my boss. (Workplace)
The dude in the blue is the big man. (Workplace)
関係代名詞の省略：基本のまとめ
能動態の省略
- who is playing playing
- that are running running
- which was shining shining
受動態の省略
- which was built built
- who were injured injured
- that is known known
削除される要素
- 関係代名詞 who, which, that
- Be動詞 is, are, was, were
メリット
- 簡潔さ Shorter sentences
- 流暢さ More natural English
- 明快さ Easier to read
フルセンテンス vs 省略形
この関係代名詞は省略できる？
その節は名詞を説明していますか？
関係代名詞（who, which, that）を含んでいますか？
be動詞 ＋ V-ing または 過去分詞 の形ですか？
活用シーン別：省略の形
能動 (-ing)
- • The man `talking`...
- • The book `lying`...
- • The students `studying`...
受動 (-ed)
- • The car `damaged`...
- • The food `ordered`...
- • The documents `signed`...
よく使われる場面
- • メール
- • ニュースの見出し
- • 人物・物の描写
- • 学術的な文章
レベル別の例文
The girl in the park is my friend.
La niña en el parque es mi amiga.
The man with the dog is tall.
El hombre con el perro es alto.
Look at the cat on the wall.
Mira al gato en la pared.
The coffee on the table is cold.
El café en la mesa está frío.
The people waiting for the bus are cold.
La gente que espera el autobús tiene frío.
I live in a house built in 1990.
Vivo en una casa construida en 1990.
The boy playing football is my brother.
El niño jugando fútbol es mi hermano.
Do you like the cake made by my mom?
¿Te gusta el pastel hecho por mi mamá?
The car parked outside belongs to the boss.
El coche aparcado fuera pertenece al jefe.
Anyone wanting to join the club should sign here.
Cualquiera que quiera unirse al club debe firmar aquí.
The letter sent yesterday was very important.
La carta enviada ayer era muy importante.
I saw a man running down the street.
Vi a un hombre corriendo por la calle.
The methodology used in this study is innovative.
La metodología utilizada en este estudio es innovadora.
Candidates applying for the job must speak English.
Los candidatos que soliciten el trabajo deben hablar inglés.
The issues discussed at the meeting were complex.
Los temas discutidos en la reunión eran complejos.
The bridge, damaged by the storm, is now closed.
El puente, dañado por la tormenta, está ahora cerrado.
The theory, first proposed in 1920, is still relevant.
La teoría, propuesta por primera vez en 1920, sigue siendo relevante.
The individual responsible for the breach has been identified.
El individuo responsable de la brecha ha sido identificado.
None of the participants, having been warned, chose to leave.
Ninguno de los participantes, habiendo sido advertidos, decidió irse.
The artifacts, discovered deep underground, are priceless.
Los artefactos, descubiertos a gran profundidad, no tienen precio.
The silence, broken only by the ticking clock, was eerie.
El silencio, roto solo por el tictac del reloj, era inquietante.
The legislation, as currently drafted, poses significant risks.
La legislación, tal como está redactada actualmente, plantea riesgos significativos.
The suspect, seen fleeing the scene, remains at large.
El sospechoso, visto huyendo de la escena, sigue prófugo.
The city, once thriving, is now a shadow of its former self.
La ciudad, una vez próspera, es ahora una sombra de lo que fue.
間違えやすい
Both use the -ing form, but a gerund is a noun, while a reduced clause is an adjective.
In regular verbs, the -ed form looks the same for both.
Learners think dropping 'that' in 'The book (that) I read' is the same as reduction.
よくある間違い
The boy who in the garden.
The boy in the garden.
The car is red parked here.
The red car parked here is mine.
The man with dog.
The man with the dog.
The girl is sitting there is my sister.
The girl sitting there is my sister.
The cake making by my mom.
The cake made by my mom.
The people who waiting.
The people waiting.
I saw a movie was interesting.
I saw an interesting movie.
The man stolen the car was caught.
The man who stole the car was caught.
The book written I read it.
The book written by him was good.
The students not study failed.
The students not studying failed.
The results, having obtained, were analyzed.
The results, having been obtained, were analyzed.
文型パターン
The person ___ (verb-ing) is my ___.
I found a ___ ___ (verb-ed) in the ___.
Anyone ___ (verb-ing) to ___ must ___.
The ___, ___ (verb-ed) by ___, was ___.
Real World Usage
I am a professional dedicated to achieving results.
Thousands displaced by floods.
See the girl dancing?
The evidence presented in Chapter 2...
Pasta served with a creamy sauce.
Follow the signs pointing toward the exit.
Be動詞を見つけよう！
The girl who is dancing...は
The girl dancing... にできます。能動か受動か、それが問題だ
The person calling youと
The person called youでは意味が正反対になります！
声に出して読んでみて！
The book written by herのように、流れるように聞こえれば大成功です。
ネイティブっぽさを出すコツ
The car parked outsideのように短く効率的な表現を選んでいます。
ニュースの見出しで練習
Man arrested for theftのような表現をニュースサイトで探して、元の形を想像してみましょう。
Smart Tips
Try deleting them! 90% of the time, the sentence will sound better and more professional.
Use a prepositional phrase reduction instead of a full clause.
These are perfect for -ing reductions in technical writing.
Just keep the V3 (past participle) and lose the rest.
発音
Reduced Stress
In reduced clauses, the participle (-ing or -ed) usually receives less stress than the noun it modifies.
Linking
The final consonant of the noun often links to the vowel of the participle.
Non-restrictive pause
The car, [pause] damaged in the crash, [pause] was totaled.
The pauses (commas) indicate the information is extra, not essential for identification.
暗記しよう
記憶術
Drop the 'Whiz' (Who/Which/That + Is/Was) to make your sentence a whiz!
視覚的連想
Imagine a pair of scissors cutting out the words 'who is' from a sentence strip, making the two remaining ends snap together perfectly.
Rhyme
If the noun is doing the act, use -ing to keep it compact. If the noun is being served, the -ed form is what's deserved.
Story
A busy editor named 'Red' (for Reduction) hates long sentences. Every time he sees 'who is' or 'which was', he deletes them with his red pen to make the newspaper fit on one page.
Word Web
チャレンジ
Look at the last three emails you sent. Find one relative clause and reduce it. Does it sound better?
文化メモ
In Western academic culture, using reduced relative clauses is seen as a sign of high-level literacy and professional 'distance'.
Newspaper headlines in English-speaking countries almost always use reduced forms to save space and create a sense of urgency.
Legal documents use reduced clauses to be extremely precise about which 'party' or 'item' is being discussed without repeating 'which is' hundreds of times.
The term 'Whiz-deletion' was coined by generative grammarians in the 1970s to describe the deletion of 'Who/Which' + 'Is'.
会話のきっかけ
Do you know the person sitting next to you?
What's the most interesting book written in your language?
Have you ever seen a movie filmed in your hometown?
In your opinion, what are the main challenges facing the world today?
日記のテーマ
よくある間違い
Test Yourself
The student ___ for the exam seemed nervous.
The car damaging in the accident needed repairs.
Choose the correct sentence:
Score: /3
練習問題
8 exercisesThe man who is standing by the window is my uncle.
The car ___ (repair) yesterday is working now.
Find and fix the mistake:
The girl who singing is very talented.
Anyone ___ (want) to leave early must ask for permission.
1. The book that is on the table. 2. The man who was arrested. 3. The path that leads home.
I saw a dog. It was barking at the mailman.
The cake eaten by the boy was chocolate.
Find the odd one out.
Score: /8
Practice Bank
12 exercisesThe old house ___ on the hill is haunted.
The decision making by the committee was controversial.
正しい文はどれですか？
英語に訳してください：'教授によって書かれた文書は非常に明確だ。'
単語を並べ替えて正しい文を作ってください：
正しい組み合わせを選んでください：
The new phone `____` with advanced features is quite expensive.
The students discussing the project needs more time.
正しい文を選んでください：
英語に訳してください：'調査から得られた情報は極めて重要だ。'
文を組み立ててください：
文をマッチさせてください：
Score: /12
よくある質問 (8)
No. You can only reduce a relative clause if the relative pronoun (who, which, that) is the **subject** of the clause. If it's the object, you can't use this method.
Generally, no. It only changes the style and tone, making it more concise. However, in some cases, it can make a sentence feel more 'permanent' or 'characteristic'.
No, clauses starting with `whose` cannot be reduced using the Whiz-deletion method. They must remain full clauses.
Both are possible but have different meanings. 'The concerned people' means they are worried. 'The people concerned' (reduced clause) means the people involved in the matter.
Yes! 'The man who was running' becomes 'The man running'. The -ing form doesn't mean 'present'; it means 'active'.
They are used in both! However, they are especially common in formal writing (academic, legal) to save space and sound objective.
You change the main verb to its -ing form. 'The path that leads home' becomes 'The path leading home'.
Yes. Place 'not' before the participle: 'Students not living on campus must pay a fee.'
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Participio adjetival
Spanish present participles cannot modify nouns directly.
Participe présent / passé
English reduced clauses are common in speech; French ones are mostly literary.
Partizipialattribut
Word order: German puts the reduced phrase before the noun.
連体修飾 (Rentai shuushoku)
No relative pronouns exist, and the modifier always comes first.
اسم الفاعل / اسم المفعول
Agreement in definiteness is required in Arabic.
的 (de) construction
Chinese modifiers always precede the noun and use 'de'.
Learning Path
Prerequisites
関連動画
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