Grammar Rule in 30 Seconds
Use 'can' to talk about skills, physical abilities, or things you know how to do right now.
- No 'to' after can: 'I can swim', not 'I can to swim'.
- No '-s' for he/she/it: 'She can sing', not 'She cans sing'.
- Use 'can't' for negatives: 'I can't drive' is the standard contraction.
Overview
can を使っているんだ。この小さな単語は、英語における究極のスーパーパワーだよ。スキルや能力について話すとき、一番頼りになるツールだね。ゲームのハイスコアを自慢するときも、Zoom面接でスキルを列挙するときも、can は親友みたいなものさ。シンプルで速くて、誰が話していても形が変わらない。複雑な語尾変化や変な変更を心配する必要はないよ。これは動詞界の「スイスアーミーナイフ（万能ナイフ）」だね。肉体的な技から精神的な才能まで、あらゆることをカバーしてくれる。このガイドでは、君がプロのようにこれを使いこなせるようにするよ。推測はおしまい。気まずい間違いもなし。ただ明確で自信に満ちた英語があるだけ。それに、パスタを焦がさずに料理できない理由を説明しようとするより、ずっと簡単だしね。How This Grammar Works
can を「modal verb（法助動詞）」として考えてみて。これは単に「助っ人」だと言うためのおしゃれな言い方さ。メインの動作動詞が「何が可能か」を示すのを助けるんだ。一番クールな点は？こいつは怠け者なんだよ。形を決して変えない。「彼」や「彼女」のために -s を足す必要はない。過去形のために -ed を足す必要もない。ただ can のままでいいんだ。どのパーティーにも同じパーカーを着ていく友達みたいなものさ。いつだって馴染むんだ。あと、この後ろに to を使うこともない。can swim であって、can to swim じゃないよ。メインの動詞は一番シンプルな形のまま。これで君の人生はずっと楽になるはず。文法の計算じゃなくて、言いたいことに集中できるからね。素早いテキストメッセージや速い会話に最適だ。ただ覚えておいて：can + 原形動詞 = 成功。英語の文法における「チートコード（裏技）」に一番近いものだよ。ギターを弾くのを覚えるのもこれくらい簡単だったらよかったのに！
Formation Pattern
can で文を作るのは、レゴブロックで遊ぶようなものだ。ただカチッとはめるだけ。これが成功の秘密のレシピだよ：
-ing も -s も -ed もなし。
not を足すだけ。大抵は can't に短縮しちゃうね。友達とチャットするときはそっちの方がずっと自然に聞こえるよ。質問の場合は、主語と can を入れ替えるだけ。ちょっとしたダンスの動きみたいだね。
I can code | 私にはコードを書くスキルがある
She can't sing | 彼女には歌うスキルがない
Can they play? | 彼らにはプレイする能力がある？
Yes, I can | 能力の肯定（うん、できるよ）
No, she can't | 能力の否定（ううん、できない）
When To Use It
can を使うよ。- General Skills（一般的なスキル）: 学んで身につけたもの。コーディング、スペイン語を話すこと、車の運転なんかを想像して。「I
candrive an Uber.（Uberの運転ができる）」 - Physical Abilities（身体能力）: 今、体が実行できること。「He
canrun a marathon.（彼はマラソンを走れる）」とか「Icantouch my toes.（つま先に手が届く）」（調子が良い日はね）。 - Mental Abilities（知的能力）: 脳が行うこと。「She
cansolve complex math problems.（彼女は複雑な数学の問題が解ける）」
can finally cook a five-course meal!（ついにフルコース料理が作れるようになった！）」とか、TikTokのコメント：「How can you dance like that?（どうやったらあんな風に踊れるの？）」を考えてみて。仕事探しにも不可欠だね。Zoom面接で、「I can manage large teams efficiently.（私は大規模なチームを効率的に管理できます）」と言うかもしれない。これは自信の言語なんだ。ただ、「I can finish this project in five minutes.（このプロジェクトは5分で終わらせられます）」みたいに、実際にはできないことを約束するのに使っちゃだめだよ。それが嘘だって僕らは知ってるからね。
Common Mistakes
- The
ToTrap（Toの罠）: 決してI can to swim.
と言わないこと。頑張りすぎてるように聞こえるよ。ただI
と言おう。canswim. - The Third Person
S（三人称のS）:He cans cook.と言っちゃだめ。金属の缶詰（cans）に食べ物を詰めてるみたいに聞こえるから。He
と言おう。cancook. - The Past Tense Mix-up（過去形の混同）:
Canは現在のためだけのもの。子供時代のことを話すなら、couldを使って。 - The Double Modal（二重助動詞）:
I will can go.
とは言わない。I will be able to go
を代わりに使おう。canは他の助動詞とスポットライトを共有するのが嫌いなんだ。 - Double Negatives（二重否定）: "I can't do nothing.« は避けよう。»I
can'tdo anything." を使うこと。ずっと賢く聞こえるよ。
Contrast With Similar Patterns
can には be able to という名前の従兄弟がいるんだ。彼らはほとんど同じ仕事をするけど、雰囲気が違う。- Can: こっちは「クールな」従兄弟。カジュアルで素早くて、90%の場合に使われる。友達や家族、ほとんどのメールで使って。
- Be able to: こっちは「スーツにネクタイ」の従兄弟。よりフォーマルだ。公式文書や、文法的に
canが使えない場合（willの後とか）に使うよ。
I can help you（自然）vs I am able to help you（とても堅苦しい）。
know how to もあるね。これは特に学習したスキルに使うんだ。I know how to fix a computer はそれを勉強したことを意味する。I can fix a computer は単に能力があることを意味するだけ。ほとんどの場合、短いから can が勝者になるね。正直なところ、移動中にメールしてるときは短い文の方がみんな好きでしょ？Quick FAQ
cannot は can't と同じ？
うん、でも cannot はとてもフォーマルだ。人生の99%は can't を使おう。時間と息の節約になるよ。
can は許可にも使える？
もちろん！
Can I borrow your charger?（充電器借りていい？）なぜ I am canning と言わないの？
なぜなら can は modal verb（法助動詞）だから。これには -ing 形がないんだ。それが必要なら、being able to を使って。
can は未来の能力にも使える？
普通は
will be able toを使うよ。でも、予定されたイベントなら時々
can を使う。「I can meet you tomorrow at 5.（明日5時に会えるよ）」みたいにね。
本当にできることを強調したいときはどうする？
I can indeed や I definitely can と言えるよ。ただ叫ばないでね、それは変だから。
Present Tense of 'Can'
| Subject | Affirmative | Negative | Question |
|---|---|---|---|
|
I
|
can
|
can't / cannot
|
Can I...?
|
|
You
|
can
|
can't / cannot
|
Can you...?
|
|
He/She/It
|
can
|
can't / cannot
|
Can he/she/it...?
|
|
We
|
can
|
can't / cannot
|
Can we...?
|
|
They
|
can
|
can't / cannot
|
Can they...?
|
Contractions
| Full Form | Contraction | Usage |
|---|---|---|
|
cannot
|
can't
|
Standard spoken/informal written
|
|
can not
|
n/a
|
Rarely used except for emphasis
|
|
can
|
n/a
|
No affirmative contraction exists
|
Meanings
Expresses that a person or thing has the power, skill, or opportunity to perform a specific action in the present.
Physical/Mental Ability
Having the inherent power or learned skill to do something.
“He can lift 100 kilograms.”
“She can solve complex math problems in her head.”
General Possibility
Expressing that something is possible or allowed by circumstances.
“You can buy stamps at the post office.”
“We can see the mountains from our window.”
Informal Permission
Asking for or giving permission in casual settings.
“Can I use your phone?”
“You can go home now if you're finished.”
Requests
Asking someone to do something for you.
“Can you help me with this bag?”
“Can you pass the salt, please?”
Reference Table
| 主語 | Can（肯定） | Can（否定） | Can（疑問） | 短い答え |
|---|---|---|---|---|
|
I
|
I can speak.
|
I can't / cannot speak.
|
Can I speak?
|
Yes, I can. / No, I can't.
|
|
You
|
You can sing.
|
You can't / cannot sing.
|
Can you sing?
|
Yes, you can. / No, you can't.
|
|
He/She/It
|
He can dance.
|
He can't / cannot dance.
|
Can he dance?
|
Yes, he can. / No, he can't.
|
|
We
|
We can play.
|
We can't / cannot play.
|
Can we play?
|
Yes, we can. / No, we can't.
|
|
They
|
They can run.
|
They can't / cannot run.
|
Yes, they can. / No, they can't.
|
フォーマル度スペクトル
I was wondering if you might be able to assist me? (Requesting assistance)
Can you help me with this, please? (Requesting assistance)
Can you give me a hand? (Requesting assistance)
Yo, can you help a brother out? (Requesting assistance)
「Can」の使い方
能力
- スキル She can play guitar.
- 容量 My phone can store 1TB.
許可
- 尋ねる Can I leave?
- 与える You can go now.
可能性
- 一般的 It can be cold in winter.
- 特徴 Stress can cause headaches.
お願い
- カジュアル Can you help me?
- 直接的 Can you close the door?
「Can」とよくある間違いの比較
「Can」使用決定フロー
誰かの能力、スキル、または容量について話したいですか？
許可を求めたり、与えたりしますか？
一般的な可能性や特徴を説明していますか？
カジュアルで直接的なお願いをしていますか？
現代の文脈での「Can」
オンラインチャット
- • Can you send that meme?
- • I can join the group call.
- • Who can help with this doc?
注文・アプリ
- • Can I add a note?
- • You can track your order.
- • Can you deliver by 7?
勉強・仕事
- • I can present next.
- • Can we meet on Zoom?
- • This tool can automate tasks.
ソーシャルメディア
- • She can really dance! #talent
- • Can you believe this view?
- • I can't even! 😂
レベル別の例文
I can swim.
Can you help me?
She can't cook.
They can speak English.
You can buy bread at the bakery.
Can I open the window?
He can play the guitar very well.
We can't come to the party tonight.
I can't find my keys anywhere.
Can you tell me how to get to the station?
You can see the whole city from the top of the tower.
If you finish early, you can go home.
It can be quite difficult to find a job these days.
I can't have left my phone at the restaurant.
Can you believe how much he has changed?
The software can handle multiple tasks simultaneously.
One can only imagine the impact of such a decision.
The results can be interpreted in several ways.
I can't help but feel that we've made a mistake.
Can it be that she was lying all along?
The sheer scale of the disaster can hardly be overstated.
As far as I can gather, the deal is still on.
He can be quite the charmer when he wants to be.
Such behavior can but lead to trouble.
間違えやすい
Learners often use 'could' for present ability because they think it's just a more polite version of 'can'.
Traditional grammar says 'may' is for permission and 'can' is for ability.
Learners try to combine them to talk about future ability.
よくある間違い
I can to swim.
I can swim.
He cans play.
He can play.
I no can go.
I can't go.
Can you to help?
Can you help?
I don't can dance.
I can't dance.
I will can come.
I will be able to come.
She can sings.
She can sing.
I can't to find it.
I can't find it.
I haven't canned.
I haven't been able to.
Can you may help?
Can you help? / May you help?
It can't have been true.
It can't have been true.
文型パターン
I can ___ very well.
Can you ___ for me, please?
You can't ___ in this area.
It can be ___ to ___.
Real World Usage
I can use Microsoft Excel at an advanced level.
Can u come over later?
Can I have the burger without onions?
Where can I buy a bus ticket?
I can't even! 😍
I can't move my arm very well.
「can」を短いシナリオで練習しよう
What can I do today?)」とか、「私のスマホは何ができないかな？ ("What can't my phone do?")」と自問自答してみてください。例えば、食べ物の注文など、実際の状況で使うと覚えやすいですよ！
「can」の後に「to」をつけないで
「Can't」と「cannot」の使い分け
丁寧なお願い：「could」と「can」
一般的な可能性を表す「can」
Smart Tips
Swap 'can' for 'be able to' to sound more professional.
Use 'Could I have...' instead of 'I want...' or 'Can I have...'.
Remember: Modals are 'to-allergic'. If you see 'can', delete the 'to' immediately.
Listen for the 't' in 'can't'. If you don't hear a 't' but the word is long, it's probably negative.
発音
The Weak 'Can'
In affirmative sentences, 'can' is usually unstressed and sounds like /kən/ (rhymes with 'run').
The Strong 'Can'
In short answers or for emphasis, 'can' is stressed and sounds like /kæn/ (rhymes with 'pan').
The Stressed 'Can't'
The negative 'can't' is always stressed and has a long /æ/ or /ɑː/ sound depending on the dialect.
Rising Intonation
Can you help? ↗
Standard yes/no question
Falling Intonation
I can't do it. ↘
Definitive statement of inability
暗記しよう
記憶術
CAN: C-apability, A-bility, N-ow. It's what you are capable of doing right now!
視覚的連想
Imagine a 'Can' of soda with a superhero cape. The 'Can' has the power to do anything! When you see a can, think of your own superpowers (skills).
Rhyme
No 'to', no '-s', 'can' is the best for the ability test!
Story
Meet Sam. Sam is a 'Can-do' person. He can speak five languages, he can climb mountains, and he can even bake a cake. But today, he can't go outside because it's raining. He can stay home and read instead.
Word Web
チャレンジ
Write down 5 things you can do and 5 things you can't do. Then, ask a friend if they can do those same things.
文化メモ
While 'may' is technically more correct for permission, using 'can' is standard. If a teacher says 'I don't know, CAN you?' when you ask 'Can I go to the bathroom?', they are making a joke about your physical ability vs. permission.
In professional emails, 'be able to' is often used to sound more polite and capable than the simple 'can'.
Australians often use 'can' in very casual, shortened requests, sometimes dropping the subject in very informal speech.
Derived from the Old English 'cunnan', which meant 'to know' or 'to know how to'.
会話のきっかけ
What is one thing you can do that most people can't?
Can you speak any other languages besides English?
If you could have any superpower, what would it be and what could you do with it?
Can you tell me about a time you couldn't do something, but then you learned how?
日記のテーマ
よくある間違い
Test Yourself
My brother ___ play the guitar really well.
Find and fix the mistake:
She can to speak three languages.
Choose the correct sentence:
Arrange the words in the correct order:
All words placed
Click words above to build the sentence
Score: /4
練習問題
8 exercisesWhich of these is correct?
I ___ (not / can) come to the meeting tomorrow.
Find and fix the mistake:
Can you to help me with my homework?
I know how to play the violin.
A: Can you drive a car? B: No, ___.
'Can I use your pen?'
French / she / speak / can't / very / well
1. Can you swim? 2. Can I go? 3. Can it rain?
Score: /8
Practice Bank
12 exercisesA: ___ I borrow your charger? B: Of course!
My cat ___ climb trees easily, but it ___ get down by itself.
If you work hard, you ___ achieve anything you set your mind to.
My old phone cannot to run that new game.
When I was younger, I can lift heavy weights.
Choose the correct sentence:
Translate into English: 'Você pode me ajudar com esta caixa?'
Translate into English: 'Eu não consigo encontrar meus óculos.'
Arrange these words into a sentence:
Arrange these words into a question:
主語と正しい能力の文を組み合わせましょう：
状況に最も合う「can」の文を組み合わせましょう：
Score: /12
よくある質問 (8)
'Can' is for the present (I can swim now), while 'could' is for the past (I could swim when I was six). 'Could' is also more polite for requests.
'Can't' is much more common in speaking and informal writing. 'Cannot' is used in formal documents or for strong emphasis.
In English, you cannot put two modal verbs together. To talk about the future, use 'I will be able to'.
No, 'can' is a modal verb, and modals never change their form. It is always 'can'.
Yes, it is very common. 'Can I go?' is perfectly fine, though 'May I go?' is more formal.
'Know how to' is only for learned skills. 'Can' is for skills AND physical ability or opportunity.
In a sentence, 'can' is often short (/kən/). 'Can't' is always long and stressed (/kænt/).
Yes, we use it for general possibilities, like 'It can get very hot in July'.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Poder
Spanish conjugates 'poder' (puedo, puedes), while English 'can' never changes.
Pouvoir
French requires different forms for 'I can' (je peux) and 'we can' (nous pouvons).
Können
German conjugates the modal (ich kann, wir können).
～（ら）れる / ことができる
English uses a separate word ('can') before the verb, while Japanese modifies the verb itself.
يستطيع (yastati'u)
Arabic requires the second verb to be conjugated to match the subject.
会 (huì) / 能 (néng)
English uses 'can' for both learned skills and physical ability.
Learning Path
Prerequisites
Continue With
Could: 過去のスキルについて話す
Overview 昔の自分の写真を見て、「うわ、あの頃はイケてたな（I really had moves）」なんて思ったことない？高校で陸上のスタ...
Could: 丁寧な依頼
### Overview 英語で依頼をする際、相手に失礼にならないよう、あるいはより丁寧な印象を与えるために欠かせないのが `could`...
Can を伴う仮定法第一形 (未来の可能性と許可)
Overview Uberの代金を誰が払うか友達と交渉したことはありますか？あるいは、真夜中までに3,000単語のレポートを書き終えたら、...
論理的な不可能性（ありえない！）
### Overview 英語で、ある状況や出来事がありえない、論理的に不可能だと強く確信していることを伝えたい時があります。そのよ...
関連動画
Related Grammar Rules
第一条件: Unless = If Not
友達に「新築祝いのパーティーには絶対行くけど、上司に残業をさせられなければね」と説明しようとしたことはありませんか？ `I...
ゼロ条件法: 習慣と日課
Overview 日が沈むと同時にスマホが自動的にダークモードに切り替わることに気づいたことがありますか？あるいは、Netflixを開く...
混合仮定法：過去の行動、現在の結果 (Type 2)
### Overview 英語学習において、中級から上級（B2レベル）へとステップアップする際、避けては通れないのが「仮定法」の高度な...
Suppose & Supposing: もしものゲーム
### Overview 英語の文法において、`suppose` と `supposing` は、聞き手を思考実験に誘い込むための特別な仮定法接続詞として...
フォーマルな転換句：「そうは言っても」など
### Overview 英語学習がC2レベルに達した学習者の皆さんにとって、単なる文法的な正しさは通過点です。次に目指すべきは、論理...
