JLPT N2・N5 Vocabulary – Difference between “危ない” and “危うい”
Table of Contents
1. Difference between “危ない” and “危うい”
2. 危ない
3. 危うい
4. Let’s Compare
5. Summary
6. Quiz
7. Similar Articles
8. Comment
Q: Do “危ない” and “危うい” have different meanings?
A: Yes. Both words express danger, but “危ない” refers to visible or immediate danger, while “危うい” is used for instability in outcomes or continuity.
危ない (JLPT N5)
[Meaning]
① Something bad is likely to happen as a result
② A situation that seems likely to fail very soon
③ Poor prospects or an uncertain future
④ Low reliability; something unclear or untrustworthy
⑤ An unstable situation that lacks a sense of security
[Examples]
夜道は危ないよ。（①）
The street at night is dangerous.
祖母の命が危ないから、覚悟しています。（②）
My grandmother’s life is in danger, so we’re prepared for the worst.
このまま円安が続くと日本の経済は危ないね。（③）
If the weak yen continues, Japan’s economy might be in trouble.
投資の話？危なくない？（④）
An investment deal? Doesn’t that sound risky?
古くて危なそうな橋だね。（⑤）
That old bridge looks unsafe.
“危ない” can generally be divided into two main types of situations:
• Direct, physical danger (①②)
• High-risk or unstable situations (③④⑤)
First, “危ない” is used when there is an immediate danger, especially in situations involving traffic accidents or threats to life, where quick reaction is necessary.
[Examples]
前から車が来てる！！危ない！！
A car is coming this way! Watch out!
火事だ！危ないから、すぐに逃げろ！！
There’s a fire! It’s dangerous—get out of here now!
医者によると、母の命は危ないようです。
According to the doctor, my mother’s life is in danger.
It is also used not only for immediate danger, but in predictive situations like “If things continue like this, something bad might happen.”
[Examples]
夜道は危ないから、一人で出かけないほうがいいよ。
It’s dangerous to walk alone at night, so you shouldn’t go out by yourself.
⇒ This expresses the possibility that something dangerous may happen as a result.
Next, “危ない” is also used in situations that are unreliable, unstable, or high-risk.
[Examples]
このままだと会社の経営が危ないかもしれない。
If things stay like this, the company might be in trouble.
⇒ This suggests concern about the company’s future, such as the possibility of bankruptcy.
あの人はよく嘘をつくし、危ない人だよ。
That person lies a lot—he’s not someone you can trust.
⇒This means the person is untrustworthy.
彼は酔っぱらっていて足元が危ないです。
He’s drunk, and his footing is unsteady.
⇒This describes an unstable way of walking.
危うい (JLPT N2)
[Meaning]
① A state where the success or existence of something is unstable and uncertain
② A risk that life, an organization, or something important may face a worst-case scenario
③ A situation where something is narrowly avoided or achieved—expressing the meaning of “just barely”
[Examples]
計画が実現できるか危ういです。（①）
It’s uncertain whether the plan can be carried out.
医師によると、父の命が危ういそうです。（②）
According to the doctor, my father’s life is in a critical condition.
危うく電車に乗り遅れるところだったよ。（③）
I almost missed the train.
“危うい” is a word that expresses a more abstract and internal sense of instability compared to “危ない”. It is used in situations involving uncertainty about the success or continuation of something, matters of life and death, or narrowly avoided outcomes.
・When expressing instability in success or continuation
[Examples]
Aチームが勝つと思っていたけど、危うくなってきたね。
I thought Team A was going to win, but now it’s looking uncertain.
⇒ There’s now a possibility that Team A might lose. The outcome has become uncertain.
多額の借金で会社の経営が危ういようです。
Due to a large amount of debt, the company’s future seems uncertain.
⇒The debt has made the company’s continued existence unstable.
・「ぎりぎり〜だ」を表す場合
[Examples]
危うく遅刻するところだったよ。
I almost arrived late.
⇒ If I had been just a bit slower, I would have been late—meaning I barely made it on time.
急ブレーキをかけなかったら、危うく事故になるところでした。
If I hadn’t slammed on the brakes, I would have almost gotten into an accident.
⇒ This means the accident was narrowly avoided at the last moment.
Let’s Compare
Both “危ない” and “危うい” express the idea of danger, but there is a clear difference in how they are used. In the following case, which expression is appropriate?
[Examples]
① そっちは危ないよ！こっちに来なさい！
② そっちは危ういよ！こっちに来なさい！
In this case, the correct answer is ① “危ない”. This situation involves immediate, physical danger or the strong possibility that something bad is about to happen, so “危ない” is the more natural choice.
Now, what about the next example? Both options are grammatically correct, but the nuance is different.
[Examples]
① 祖母の命が危ないので、急いで病院へ行きました。
My grandmother’s life was in immediate danger, so I rushed to the hospital.
② 祖母の命が危ういので、急いで病院へ行きました。
My grandmother’s life seemed to be gradually declining, so I rushed to the hospital.
① expresses an urgent situation where someone’s life is in immediate danger.
② expresses a gradually worsening condition, where the person’s life may be in danger if things continue as they are.
In this way, “危ない” is used when reacting to an immediate, visible danger, while “危うい” is used when the course of events or condition is unstable and there is uncertainty about what lies ahead.
Summary
| Meaning | Nuance | Common usage situations | |
| 危ない | [Direct or physical danger] ① Something bad is likely to happen as a result ② It seems about to fail at any moment [High-risk situations] ③ The future is uncertain; the outlook is bleak ④ Untrustworthy or unclear ⑤ The situation is unstable (physically or mentally) | Expresses immediate danger, low reliability, or anxiety about the future. | ・Emergency situations involving accidents or life-threatening conditions ・When there are doubts about the reliability of a person or thing ・When there is concern about business operations or the outlook for the future |
| 危うい | ① The success or continuation of something is unstable ② There is a risk of reaching a worst-case scenario, such as death or collapse ③ A situation where something was narrowly avoided or barely achieved (“just in time”) | Used in slightly abstract contexts to express instability in the success, structure, survival, or continuation of something. | ・Situations involving life, business, or competitions where continuation is uncertain ・Outcomes that were narrowly decided or just barely achieved |
Quiz
Read the following sentence and choose the expression that fits the context from the options provided in the parentheses.
Click on the question to check the answer.
A. 危ない
この橋は老朽化していて、渡るのはちょっと危ないです。
This bridge is old and worn out, so it feels a bit dangerous to cross.
*”危ない” is appropriate here because the danger is physical due to structural aging.
A. 危うい
資金が底をつきそうで、プロジェクトの継続が危うい。
The project’s continuation is in doubt as funds are nearly depleted.
*”危うい” is suitable because it expresses instability in whether the project can continue.
A. 危うく
危うく転びそうになったけど、なんとか踏ん張りました。
I almost fell but managed to keep my balance.
*”危うく～するところだった” is used to express a “narrowly avoided” situation.
A. 危ない
知らない番号からの電話って、なんか危ない気がする。
I get a bad feeling from phone calls from unknown numbers—they seem suspicious.
*”危ない” is used when something seems untrustworthy or shady.
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