関係代名詞って聞くと難しそうに感じるかもしれないけど、実は2つの文をスマートに1つにまとめる便利な道具なんだ。これをマスターすると、英語の文章がぐっと自然になって、長文読解も楽になるよ。
英語コミュニケーション
数学
理科
その他
TOEIC
国語Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
15
•
Updated May 8, 2026
•
関係代名詞を学ぼう: 文を豊かにする方法
1 / 5
関係代名詞の基本とルール
関係代名詞を使えば「私は一人の少年を知っています。彼はサッカーがとても上手です」みたいな2つの文を、**「私はサッカーがとても上手な一人の少年を知っています」**という1つの自然な文にできる。これが関係代名詞の魔法だ！
どの関係代名詞を使うかは、先行詞（説明される名詞）が「人」か「もの・動物」かと、その関係代名詞が文の中で「主語」か「目的語」かで決まる。
人の場合は主格も目的格もwho、もの・動物の場合は主格も目的格もwhichを使う。迷ったときはthatが万能選手として使えるから覚えておこう。
💡 テストのコツ: 関係代名詞の後ろが「動詞」なら主格、「主語+動詞」なら目的格！これさえ覚えれば格の判断はバッチリ。
主格の関係代名詞の使い方
主格の関係代名詞は、関係代名詞のすぐ後ろに動詞が来るのが最大の特徴だ。「〜する先行詞」という感じで訳せばOK。
人が先行詞の場合：「I have a friend. + She lives in Osaka.」→ 「I have a friend who lives in Osaka.」（大阪に住んでいる友達がいます）
もの・動物が先行詞の場合：「I saw a cat. + It was sleeping.」→ 「I saw a cat which was sleeping under the car.」（車の下で眠っている猫を見ました）
どちらも関係代名詞の直後に動詞（lives, was sleeping）が来ているのがポイント。これを見つけられれば主格だと一発で分かる。
💡 覚え方: 主格は「関係代名詞+動詞」のセットで覚えよう！
目的格の関係代名詞と省略
目的格の関係代名詞は、関係代名詞のすぐ後ろに「主語+動詞」が来る。そして一番大事なのは、目的格は省略されることがめちゃくちゃ多いということ！
人が先行詞：「The boy is my brother. + You met him yesterday.」→ 「The boy (who) you met yesterday is my brother.」（昨日会った少年は私の弟です）
もの・動物が先行詞：「This is the picture. + My father took it.」→ 「This is the picture (which) my father took.」（父が撮った写真です）
長文で名詞のすぐ後ろに「主語+動詞」があったら、目的格の関係代名詞が省略されている可能性大。これに気づけるかどうかで長文読解の理解度が変わる。
💡 長文読解のコツ: 名詞の後に突然「主語+動詞」が出てきたら、省略された関係代名詞を頭の中で補って読もう！
実践練習とテスト対策
文を作る練習をしてみよう。「The woman is a famous singer. + She wrote this song.」を1つにする場合、まず共通部分（The woman = She）を見つけて、先行詞（The woman = 人）と格（She = 主語 = 主格）を判断する。
答えは 「The woman who wrote this song is a famous singer.」（この歌を書いた女性は有名歌手です）となる。
目的格の例：「I'm looking for the key. + I lost it this morning.」→ 「I'm looking for the key (which) I lost this morning.」（今朝なくした鍵を探しています）
テストでの鉄則：空欄の後ろを必ずチェック！後ろが動詞なら主格、主語+動詞なら目的格。この判断ミスが一番多いから要注意。
💡 得点アップ: 日本語訳は後ろから前に訳すと自然。「私が昨日読んだ本」のように関係代名詞の部分を先行詞の前に持ってこよう！
まとめ：関係代名詞完全攻略
関係代名詞の基本ルールをもう一度整理しよう。先行詞が人ならwho、もの・動物ならwhich。関係代名詞の後ろが動詞なら主格、主語+動詞なら目的格。
目的格は省略できるというのが最重要ポイント。長文でこれに気づけるかどうかが勝負の分かれ目になる。
実際の英文では省略形がとても多いから、「名詞+主語+動詞」の形を見たら「あ、関係代名詞が省略されてる！」とピンとくるようになろう。この感覚が身につけば、英語の長文がスラスラ読めるようになるはず。
💡 最終チェック: 迷ったときはthatを使えば大体OK。でもテストでは基本のwho/whichの使い分けをしっかり覚えておこう！
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content in 英語コミュニケーション
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
関係代名詞を学ぼう: 文を豊かにする方法
関係代名詞って聞くと難しそうに感じるかもしれないけど、実は2つの文をスマートに1つにまとめる便利な道具なんだ。これをマスターすると、英語の文章がぐっと自然になって、長文読解も楽になるよ。
関係代名詞の基本とルール
関係代名詞を使えば「私は一人の少年を知っています。彼はサッカーがとても上手です」みたいな2つの文を、**「私はサッカーがとても上手な一人の少年を知っています」**という1つの自然な文にできる。これが関係代名詞の魔法だ！
どの関係代名詞を使うかは、先行詞（説明される名詞）が「人」か「もの・動物」かと、その関係代名詞が文の中で「主語」か「目的語」かで決まる。
人の場合は主格も目的格もwho、もの・動物の場合は主格も目的格もwhichを使う。迷ったときはthatが万能選手として使えるから覚えておこう。
💡 テストのコツ: 関係代名詞の後ろが「動詞」なら主格、「主語+動詞」なら目的格！これさえ覚えれば格の判断はバッチリ。
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
主格の関係代名詞の使い方
主格の関係代名詞は、関係代名詞のすぐ後ろに動詞が来るのが最大の特徴だ。「〜する先行詞」という感じで訳せばOK。
人が先行詞の場合：「I have a friend. + She lives in Osaka.」→ 「I have a friend who lives in Osaka.」（大阪に住んでいる友達がいます）
もの・動物が先行詞の場合：「I saw a cat. + It was sleeping.」→ 「I saw a cat which was sleeping under the car.」（車の下で眠っている猫を見ました）
どちらも関係代名詞の直後に動詞（lives, was sleeping）が来ているのがポイント。これを見つけられれば主格だと一発で分かる。
💡 覚え方: 主格は「関係代名詞+動詞」のセットで覚えよう！
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
目的格の関係代名詞と省略
目的格の関係代名詞は、関係代名詞のすぐ後ろに「主語+動詞」が来る。そして一番大事なのは、目的格は省略されることがめちゃくちゃ多いということ！
人が先行詞：「The boy is my brother. + You met him yesterday.」→ 「The boy (who) you met yesterday is my brother.」（昨日会った少年は私の弟です）
もの・動物が先行詞：「This is the picture. + My father took it.」→ 「This is the picture (which) my father took.」（父が撮った写真です）
長文で名詞のすぐ後ろに「主語+動詞」があったら、目的格の関係代名詞が省略されている可能性大。これに気づけるかどうかで長文読解の理解度が変わる。
💡 長文読解のコツ: 名詞の後に突然「主語+動詞」が出てきたら、省略された関係代名詞を頭の中で補って読もう！
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
実践練習とテスト対策
文を作る練習をしてみよう。「The woman is a famous singer. + She wrote this song.」を1つにする場合、まず共通部分（The woman = She）を見つけて、先行詞（The woman = 人）と格（She = 主語 = 主格）を判断する。
答えは 「The woman who wrote this song is a famous singer.」（この歌を書いた女性は有名歌手です）となる。
目的格の例：「I'm looking for the key. + I lost it this morning.」→ 「I'm looking for the key (which) I lost this morning.」（今朝なくした鍵を探しています）
テストでの鉄則：空欄の後ろを必ずチェック！後ろが動詞なら主格、主語+動詞なら目的格。この判断ミスが一番多いから要注意。
💡 得点アップ: 日本語訳は後ろから前に訳すと自然。「私が昨日読んだ本」のように関係代名詞の部分を先行詞の前に持ってこよう！
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
まとめ：関係代名詞完全攻略
関係代名詞の基本ルールをもう一度整理しよう。先行詞が人ならwho、もの・動物ならwhich。関係代名詞の後ろが動詞なら主格、主語+動詞なら目的格。
目的格は省略できるというのが最重要ポイント。長文でこれに気づけるかどうかが勝負の分かれ目になる。
実際の英文では省略形がとても多いから、「名詞+主語+動詞」の形を見たら「あ、関係代名詞が省略されてる！」とピンとくるようになろう。この感覚が身につけば、英語の長文がスラスラ読めるようになるはず。
💡 最終チェック: 迷ったときはthatを使えば大体OK。でもテストでは基本のwho/whichの使い分けをしっかり覚えておこう！
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
0
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Most popular content in 英語コミュニケーション
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user