Warning: Negative Possibilities (~kanenai)
~かねない to warn that a specific action or situation might lead to a negative, undesirable outcome.
Grammar Rule in 30 Seconds
Use ~kanenai to express that something is not impossible, often implying a negative outcome might occur.
- Attach to the dictionary form of a verb: {行く|いく} → {行けなくない|いけなくない}.
- It expresses a lingering possibility of something, usually something undesirable.
- It is often used to downplay or suggest a hidden risk.
Overview
In Japanese, expressing possibility is a nuanced task. While かもしれない serves as a general-purpose "maybe," the B2-level grammar point ~かねない (~kanenai) is a specialized tool for forecasting negative outcomes. It is used when a current situation or action has the potential to lead to an undesirable result.
Think of it not as a simple guess, but as a logical inference—a warning sign that, based on present evidence, something bad is a distinct possibility. It carries the weight of "I'm afraid it might..." or "it could very well lead to..."
Unlike neutral expressions of possibility, ~かねない is exclusively reserved for situations with a negative, dangerous, or unfortunate flavor. It connects a cause (the current state) to a potential negative effect. For example, if a friend is driving too fast, you might think, 事故を起こしかねない ({じこ}をおこしかねない), meaning "(They) might cause an accident." This isn't just a random thought; it's a conclusion drawn from the observable action of speeding.
Mastering ~かねない allows you to express concern, issue warnings, and analyze risks with the precision expected of an advanced speaker.
This grammar point is derived from the verb かねる (kaneru), which means to be unable or hesitant to do something. The negative potential form, かねない, literally translates to "not unable to do," which, in this specific grammatical construction, paradoxically signifies that the negative event is possible. This linguistic origin is key to its nuance: it suggests that the circumstances are such that there is no guarantee the bad outcome won't happen.
Conjugation Table
| Form | Structure | Example Verb: する (to do) |
Translation | Notes | ||
|---|---|---|---|---|---|---|
| --- | --- | --- | --- | --- | ||
| Plain/Dictionary Form | Verb Stem + かねない |
しかねない |
Might do (and it would be bad) | The most common form, used in both casual and formal speech and writing. | ||
| Polite Form | Verb Stem + かねません |
しかねません |
Might do (and it would be bad) [Polite] | Used in professional contexts, such as business emails or formal reports. Essential for showing respect. | ||
| Past Form | Verb Stem + かねなかった |
しかねなかった |
Might have done (and it would have been bad) | Rarely used. Japanese speakers typically prefer other structures like ~ところだった or ~おそれがあった to describe a past risk that was narrowly avoided. Using ~かねなかった can sound unnatural in many contexts. |
||
| Negative Form | N/A | N/A | N/A | There is no negative form. Since ~かねない already implies a negative outcome, negating it (e.g., "might not do something bad") is linguistically redundant and is not a standard construction. You would use a different pattern entirely. |
||
| Te-Form | Verb Stem + かねなくて |
しかねなくて |
Might do..., and... | Used to connect clauses. For example: 問題を起こしかねなくて、心配だ (It might cause a problem, so I'm worried). |
How This Grammar Works
~かねない is rooted in its relationship with ~かねる. The verb 兼ねる means to find something difficult or impossible to do, often for psychological or social reasons. For instance, 賛成しかねます means "I find it difficult to agree," a polite but firm way of disagreeing.かねない is the potential negative of this verb, meaning "is not unable to." When attached to another verb's stem, it creates the specific meaning: "(The subject) is not unable to [verb], and therefore might."~かねない, you are signaling that you have observed a situation and are pointing out a likely negative trajectory. It's less about your personal feelings and more about the inherent risk in the circumstances.このままでは、会社は倒産しかねない。 (If things go on like this, the company could go bankrupt). The speaker is presenting bankruptcy not as a random fear, but as a plausible outcome based on the current state (このままでは).~かねない is so prevalent in news analysis, business reports, and serious discussions. It allows the speaker to issue a warning without sounding overly emotional or speculative. It frames the potential negative event as a logical conclusion, giving the statement an air of authority and concern.Formation Pattern
~かねない to a verb is a straightforward process. The rule is to always use the verb stem, also known as the pre-ます form.
ます form.
ます suffix to isolate the stem.
かねない (or かねません for polite speech).
かねない |
言う (to say) | 言います | 言 | 言いかねない (might say it) |
怒る (to get angry) | 怒ります | 怒り | 怒りかねない (might get angry) |
読む (to read) | 読みます | 読 | 読みかねない (misreading the rule: rarely used as reading isn't inherently negative) |
起きる (to happen/occur) | 起きます | 起き | 起きかねない (might happen) |
忘れる (to forget) | 忘れます | 忘れ | 忘れかねない (might forget) |
する (to do) | します | し | しかねない (might do it) |
来る (to come) | 来ます | 来 | 来かねない (might come - less common, context must be negative) |
引き起こす (to cause), the stem is 引き起こし, leading to 引き起こしかねない (might cause it).
When To Use It
~かねない is versatile within its negative constraints. It appears in various contexts where warning or negative forecasting is necessary.- Professional and Technical Warnings
~かねない is used to flag potential issues, risks, or system failures in a formal and objective manner. It is a standard way to express professional concern in reports, emails, and meetings.このセキュリティ脆弱性を放置すれば、情報流出を招きかねません。(If we ignore this security vulnerability, it could lead to a data leak.)そのような対応では、お客様からの信頼を失いかねません。(With that kind of response, we could lose the trust of our clients.)
- Social Commentary and News Reporting
~かねない to discuss the potential negative consequences of societal trends, political decisions, or economic policies. It adds a sense of gravity and analytical depth.急速な高齢化は、将来の社会保障システムの崩壊につながりかねない。(Rapid aging of the population could lead to the collapse of the social security system in the future.)ネットでの誹謗中傷は、時として取り返しのつかない事態を引き起こしかねない。(Online slander can sometimes cause irreversible situations.)
- Personal Advice and Interpersonal Warnings
~かねない serves as a potent warning. It’s more direct and serious than ~ほうがいい (it's better to...). It implies that the current course of action is genuinely risky.あまり無理をすると、病気になりかねないよ。(If you push yourself too hard, you could get sick.)そんなことを正直に言|ったら、彼は怒りかねないから気をつけて。(If you say that so bluntly, he might get angry, so be careful.)
- Expressing Worries and Fears
この計画、このまま進めると大な失敗に終わりかねない気がする。(I have a feeling that if we proceed with this plan as is, it could end in a major failure.)
Common Mistakes
~かねない. Avoiding these common pitfalls is crucial for accurate use.- 1Using It for Positive or Neutral Outcomes: This is the most fundamental error.
~かねないis strictly for negative results. Using it for a positive event creates a confusing and often comical sentence, implying the good outcome is actually a disaster.
- Incorrect:
この調子で頑張れば、試験に合格しかねない。(If I keep working hard at this pace, I might pass the exam.) - Why it's wrong: This frames "passing the exam" as a negative event. The listener will be confused.
- Correct:
この調子で頑張れば、試験に合格するかもしれない。
- 1Confusing
~かねないwith~かねる: This is a very common point of confusion. They come from the same root but have nearly opposite meanings in practice.~かねるmeans you cannot or are hesitant to do something.~かねないmeans something bad might happen.
ご要望にはお応えしかねます。(I am unable to meet your request.) -> Polite refusal.- そんなことをすれば批判を浴びかねない。` (If you do that, you might face criticism.) -> Warning.
- 1Incorrect Grammatical Attachment:
~かねないcan only follow a verb stem. It cannot be attached directly to nouns or adjectives. To use it with a noun or adjective concept, you must introduce a verb, typicallyなる(to become) orする(to do).
- Incorrect:
それは大問題かねない。 - Correct:
それは大問題になりかねない。(That could become a big problem.) - Incorrect:
危険かねない。 - Correct:
危険な状態になりかねない。(It could become a dangerous situation.)
- 1Misjudging the Level of Certainty:
~かねないis stronger and more grounded thanかもしれない. It implies there is a tangible reason to expect the negative outcome. Using it for a wild, baseless guess can make you sound overly dramatic. It's for plausible risks, not remote possibilities.
Contrast With Similar Patterns
~かねない competes with several other patterns, each with a distinct nuance.~かねない | Negative possibility based on a present cause. A logical warning. | Formal/Informal | このままだと赤点を取りかねない。 (At this rate, I might fail the test.) |~かもしれない | Neutral possibility. A simple guess or speculation about anything (good, bad, or neutral). | Informal (Polite: ~かもしれません) | 明日は雨が降るかもしれない。 (It might rain tomorrow.) |~おそれがある | Formal, objective risk. Used in official announcements, reports, and public warnings. Sounds very written and impersonal. | Very Formal | この地震により、津波が発生するおそれがあります。 (There is a risk of a tsunami occurring due to this earthquake.) |~可能性がある | Neutral, factual possibility. Focuses on the existence of a possibility itself. Often used in analytical or academic contexts. | Formal/Informal | 将来的には、AIが人間の仕事を奪う可能性がある。 (There's a possibility that AI will take human jobs in the future.) |- Use
~かもしれないwhen you're simply guessing. It's your go-to for everyday uncertainty. - Use
~かねないwhen you see a clear cause that could lead to a specific bad effect, and you want to warn someone or express concern. - Use
~おそれがあるfor large-scale, impersonal risks, like those you'd see on the news or in a formal report. It's much stiffer than~かねない. - Use
~可能性があるwhen you want to state neutrally that a possibility exists, without the inherent negative warning of~かねないor~おそれがある.
事故に遭うかもしれないfeels like a general, passive thought.事故に遭いかねないfeels like an active warning, prompted by the specific danger you are observing.事故に遭うおそれがあるsounds like a line from a public safety brochure, too formal for the situation.
Real Conversations
Scenario 1
Person A
田中さん、このコード、ちょっと確認してもらえませんか。特定の条件下で無限ループに陥りかねない気がして…。(Tanaka-san, could you check this code for me? I have a feeling it could fall into an infinite loop under specific conditions...)
Person B
本当だ。この処理は危険ですね。すぐ修正しましょう。これではサーバーダウンを引き起こしかねません。(You're right. This process is dangerous. Let's fix it right away. This could cause the server to go down.)
Scenario 2
Person A
最近、山本くん、全然大学に来てないね。大丈夫かな。(Yamamoto hasn't been coming to university at all recently. I wonder if he's okay.)
Person B
うん、心配だよね。このままだと単位を落として、留年しかねないよ。(Yeah, I'm worried. At this rate, he could fail his classes and might have to repeat the year.)
Scenario 3
User
すごい！でも、これ、一歩間違えたら大怪我じゃすまないよ…。安易に真似する人が出てきて、大きな事故につながりかねないから、動画は削除した方がいいんじゃない？(Wow! But if you mess that up by even one step, it won't just be a serious injury... People might try to copy it carelessly, and that could lead to a major accident. Maybe you should delete the video?)
Progressive Practice
Level 1: Choose the Correct Grammar
For each sentence, choose either ~かねない or ~かもしれない.
あんなに甘いものばかり食べていたら、病気に（なりかねない / なるかもしれない）。
天気予報によると、午後から雪が（降りかねない / 降るかもしれない）。
彼の性格からして、そんな失礼なことを（言いかねない / 言うかもしれない）。
Answers: 1. なりかねない (logical negative consequence), 2. 降るかもしれない (neutral possibility), 3. 言いかねない (warning based on character)
Level 2: Sentence Formation
Complete the sentences by putting the verb in the correct form with ~かねない or ~かねません.
(Context: Formal report) この問題を無視し続けると、顧客の信頼を (失う) __________。
(Context: Warning a friend) そんなにゲームばかりしていると、試験に (落ちる) __________よ。
(Context: Voicing a concern) 彼の運転は荒いから、事故を (起こす) __________。
Answers: 1. 失いかねません, 2. 落ちかねない, 3. 起こしかねない
Level 3: Sentence Production
Create your own warning sentence using ~かねない based on the given scenario.
Scenario: Your coworker is thinking about complaining directly to the company president about a minor issue.
Example Answer: そんなことで社長に直接文句を言ったら、逆に評価を下げられかねないよ。 (If you complain directly to the president about something like that, you could end up having your reputation damaged instead.)
Scenario: You see a news report about people gathering in a crowded space during a pandemic.
Example Answer: これだけ多くの人が密集すれば、大規模なクラスターを発生させかねない。 (If this many people are crowded together, it could cause a large-scale cluster infection.)
Quick FAQ
~かねない?~といけない?~といけない (or ~なければならない) expresses necessity or obligation ("must do"). ~かねない expresses a negative possibility ("might do"). 勉強しないといけない means "I must study." 勉強しないと、留年しかねない means "If I don't study, I might have to repeat the year."~かねない to talk about myself?このまま準備を怠ると、プレゼンで大失敗しかねない (If I neglect my preparations like this, I could fail spectacularly at the presentation).~かねなかった is rare. What should I use instead?~ところだった (was on the verge of) or ~おそれがあった (there was a risk of). For example, instead of 事故を起こしかねなかった, you would more naturally say もう少しで事故を起こすところだった (I almost got into an accident).~かねない more formal than ~かもしれない?~かねない carries a more serious, analytical, and concerned tone. While ~かもしれません is the polite form of ~かもしれない, ~かねません is simply the polite version of ~かねない.~かねない in casual conversation, but it will always make the topic sound more grave than ~かもしれない would.Formation Table
| Verb Type | Dictionary Form | Stem | Result |
|---|---|---|---|
|
Group 1
|
書く
|
書き
|
書きかねない
|
|
Group 2
|
食べる
|
食べ
|
食べかねない
|
|
Group 3
|
する
|
し
|
しかねない
|
|
Group 3
|
来る
|
来
|
来かねない
|
Meanings
Used to express that there is a possibility of something happening, usually something negative or undesirable. It implies that the speaker is worried about a potential risk.
Negative Possibility
Suggests a risk of a bad outcome.
“{雨|あめ}が{降|ふ}りかねない。”
“{遅刻|ちこく}しかねない。”
Understatement
Used to suggest something is possible without being overly direct.
“{彼|かれ}なら{やり|やり}かねない。”
“{嘘|うそ}をつきかねない。”
Reference Table
| Form | Structure | Example |
|---|---|---|
|
Affirmative
|
Verb(dict) + かねない
|
雨が降りかねない
|
|
Negative
|
Verb(dict) + かねない (rare)
|
N/A
|
|
Question
|
Verb(dict) + かねないか？
|
そんなことが起きかねないか？
|
|
Past
|
N/A
|
N/A
|
|
Polite
|
Verb(dict) + かねません
|
雨が降りかねません
|
|
Casual
|
Verb(dict) + かねない
|
それ、やりかねない
|
Formality Spectrum
彼がやりかねません。 (Discussing a friend's risky behavior.)
彼がやりかねない。 (Discussing a friend's risky behavior.)
彼ならやりかねないね。 (Discussing a friend's risky behavior.)
あいつ、やりかねんぞ。 (Discussing a friend's risky behavior.)
The Risk Spectrum
Neutral
- かもしれない might
Negative
- かねない might (risk)
Examples by Level
{雨|あめ}が{降|ふ}りかねない。
It might rain (and that's bad).
{遅刻|ちこく}しかねない。
I might be late.
{失敗|しっぱい}しかねない。
I might fail.
{忘|わす}れかねない。
I might forget.
{彼|かれ}なら{やり|やり}かねない。
He is capable of doing that (bad thing).
{事故|じこ}が{起|お}きかねない。
An accident might happen.
{問題|もんだい}になりかねない。
It might become a problem.
{混乱|こんらん}しかねない。
It might cause confusion.
{経済|けいざい}が{悪化|あっか}しかねない。
The economy might worsen.
{信頼|しんらい}を{失|うしな}いかねない。
We might lose trust.
{誤解|ごかい}を{招|まね}きかねない。
It might lead to a misunderstanding.
{大惨事|だいさんじ}になりかねない。
It could turn into a disaster.
{彼|かれ}の{態度|たいど}は{反感|はんかん}を{買|か}いかねない。
His attitude might invite resentment.
{無理|むり}をすれば{体|からだ}を{壊|こわ}しかねない。
If you overdo it, you might ruin your health.
{情報|じょうほう}が{漏洩|ろうえい}しかねない。
Information might leak.
{計画|けいかく}が{頓挫|とんざ}しかねない。
The plan might fail/stall.
{現状|げんじょう}を{放置|ほうち}すれば{深刻|しんこく}な{事態|じたい}を{招|まね}きかねない。
If we leave the current situation as is, it could lead to a serious crisis.
{感情|かんじょう}に{流|なが}されれば{判断|はんだん}を{誤|あやま}りかねない。
If you are swayed by emotions, you might make a wrong judgment.
{過度|かど}な{規制|きせい}は{市場|しじょう}の{活性化|かっせいか}を{阻害|そがい}しかねない。
Excessive regulation might hinder market revitalization.
{彼|かれ}の{発言|はつげん}は{国際的|こくさいてき}な{批判|ひはん}を{浴|あ|び}びかねない。
His remarks might invite international criticism.
{既存|きそん}の{枠組|わくぐ|み}を{踏襲|とうしゅう}するだけでは{抜本的|ばっぽんてき}な{解決|かいけつ}には{至|いた}りかねない。
Merely following existing frameworks might not lead to a fundamental solution.
{科学的|かがくてき}な{根拠|こんきょ}を{欠|か}いた{主張|しゅちょう}は{社会|しゃかい}の{混乱|こんらん}を{助長|じょちょう}しかねない。
Claims lacking scientific basis might exacerbate social confusion.
{歴史|れきし}を{忘|わす}れれば{同|おな}じ{過|あやま}ちを{繰|く|り}{返|かえ}しかねない。
If we forget history, we might repeat the same mistakes.
{技術|ぎじゅつ}の{進歩|しんぽ}は{倫理的|りんりてき}な{問題|もんだい}を{浮上|ふじょう}させかねない。
Technological progress might bring ethical issues to the surface.
Easily Confused
Both express possibility.
Common Mistakes
食べるかねない
食べかねない
行くかもしれない
行くかねない
行ったかねない
行くかねない
いいことかねない
いいことかもしれない
雨が降るかねない
雨が降りかねない
彼が来るかねない
彼が来かねない
楽しいかねない
楽しいかもしれない
成功しかねない
成功するかもしれない
遅刻するしかねない
遅刻しかねない
雨が降らないかねない
雨が降りかねない
彼が勝つかねない
彼が勝つかもしれない
Sentence Patterns
___が___かねない。
Real World Usage
台風が上陸しかねません。
納期が遅れかねない状況です。
それ、やりかねないよ笑
火災が起きかねない。
経済が混乱しかねない。
これ、炎上しかねないね。
Avoid Positives
Use in Formal Writing
Character Judgments
Indirectness
Smart Tips
Use ~kanenai to sound professional.
Use ~kanenai to show you know their character.
Use it to sound objective.
Use it to express concern.
Pronunciation
Intonation
The 'nai' at the end should have a falling intonation to sound serious.
Warning
降りかねない↓
Serious warning.
Memorize It
Mnemonic
KANE (money) + NAI (not). If you have no money, you might do something desperate (risky).
Visual Association
Imagine a person standing on a cliff edge. A sign says 'KANE-NAI' (No money). The person is wobbling, looking like they might fall.
Rhyme
When the risk is high and you're feeling the strain, use the grammar form that is ~kanenai.
Story
Kenji was broke. He stared at the store window. He thought, 'If I don't eat, I might steal.' He realized, 'I might steal' is '盗みかねない'. He decided to work instead.
Word Web
Challenge
Write 3 sentences about things you are worried might happen in your city.
Cultural Notes
Used to sound objective when delivering bad news.
Standard for reporting potential disasters.
Used to judge someone's character.
Derived from the verb 'kaneru' (to be unable to do) + 'nai'.
Conversation Starters
最近、何か心配なことはありますか？
Journal Prompts
Common Mistakes
Test Yourself
Which is correct?
彼ならそんなことを___。
Find and fix the mistake:
合格しかねない。
事故 / 起きかねない / が
He might lose his job.
Answer starts with: a...
Match each item on the left with its pair on the right:
Can I use kanenai for winning the lottery?
A: 彼は嘘をつくかな？ B: ___
Score: /8
Practice Exercises
8 exercisesWhich is correct?
彼ならそんなことを___。
Find and fix the mistake:
合格しかねない。
事故 / 起きかねない / が
He might lose his job.
Match the risk.
Can I use kanenai for winning the lottery?
A: 彼は嘘をつくかな？ B: ___
Score: /8
Practice Bank
10 exercises{寝|ね}ないと、ミスを（する）___。
He might do something that crazy.
[ 怒られ | かねない | 部長に | そんなことを言ったら ]
{個人情報|こじんじょうほう}が（___）かねない。
Match the pairs:
トラブルになりかねない。
このトレンドは{社会問題|しゃかいもんだい}に（{発展|はってん}する）___。
Economic report style:
It might break (and that would be bad).
[ 事故に | 出しすぎると | スピードを | 遭いかねない ]
Score: /10
FAQ (8)
No, it is strictly for negative outcomes.
Yes, it is quite formal.
Dictionary form + kanenai.
No, it means 'it is possible'.
Yes, but mostly in serious topics.
It will sound very strange.
No, kamoshirenai is neutral.
No, only verbs.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
podría
Kanenai is strictly negative.
pourrait
Kanenai is strictly negative.
könnte
Kanenai is strictly negative.
おそれがある
Kanenai is more personal.
قد
Kanenai is strictly negative.
可能会
Kanenai is strictly negative.
Learning Path
Prerequisites
Related Grammar Rules
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