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N5Lesson notes · Oct 6, 2026

Be careful in Japanese: 気きをつけて (ki wo tsukete) and the other ways to say it

"Be careful" in Japanese is most often 気きをつけて (ki wo tsukete) — but English uses one phrase for five different situations, and Japanese uses a different word for each.

Say goodbye to a friend, shout at someone about to step into traffic, read a sign on a staircase, tell a coworker to think hard before signing a contract, and ask a sick person to look after themselves. English: "be careful" or "take care" every time. Japanese: 気きをつけて, 危あぶない, 注意ちゅういして, 慎重しんちょうに, 無理むりしないで, and a few more. This article sorts them by situation so you can pick the right one on the first try.

The basics

What is the most common way to say "be careful" in Japanese?

気きをつけて (ki wo tsukete) is the default. It literally means "attach your spirit/attention [to it]" — 気き (ki) is your attention or mind, つける is "to attach". It works for two very different jobs, just like English: a warm goodbye ("take care") and a warning ("watch out").

気きをつけて。 — Take care. / Be careful. (casual, to a friend or family member leaving) 気きをつけてね。 — Take care, okay? (casual and soft, the ね adds warmth)

The polite versions add ください or use the お〜 prefix. 気きをつけてください is the full polite request. お気きをつけて is the smoother, more service-like version you hear from shop staff, hotel clerks and station announcements.

気きをつけてください。 — Please be careful. (polite, to a guest or a stranger) お気きをつけて。 — Please take care. (polite, shop staff and service settings, often as you leave)

How do you say what you should be careful about?

You mark the thing with the particle に: 〜に気きをつける. This is the single most useful grammar point in the whole topic, because English says "be careful of the car" or "be careful with the knife" and learners translate the preposition away.

車くるまに気きをつけて。 — Watch out for cars. (casual, to someone about to cross the road) 足元あしもとに気きをつけてください。 — Please watch your step. (polite, said by staff at an entrance with a step) 風邪かぜに気きをつけてね。 — Take care not to catch a cold. (casual, caring, common in winter)

Without に, the sentence has no target. The pattern is Noun + に + 気きをつける. The thing you must be careful about is marked with に, not を, in standard Japanese.

When can you drop the object?

In daily life you rarely name the danger. If the situation is clear, 気きをつけて alone is a complete sentence, and it is also the standard way to end a conversation with someone who is about to travel, drive, or walk home late.

じゃあ、気きをつけて。 — Well then, take care. (casual, farewell at the door) 気きをつけて帰かえってね。 — Get home safe, okay? (casual, kind, said when seeing someone off)

For more ways to end a conversation, see how to say goodbye in Japanese, where 気きをつけて sits next to さようなら and またね.

Beyond the basics

What do you shout when something is actually dangerous?

危あぶない! (abunai) — and you say it instead of 気きをつけて. By the time you have finished saying 気きをつけて, the glass has already fallen. 気きをつけて is advice for a situation that is still developing. 危あぶない is a reflex for the half-second before impact.

危あぶない! — Watch out! / Look out! (shouted, immediate danger, any register) 危あぶないから、下さがって。 — It's dangerous, so step back. (casual, a short explanation after the first shout)

This is the first thing to fix in a learner's Japanese. A natural pair is: shout 危あぶない! first, then follow with 気きをつけて once everyone is safe. The full word family, including 危険きけん and 危あぶない場所ばしょ, is in our article on dangerous in Japanese.

What does the command form 気きをつけろ sound like?

気きをつけろ is the plain command form. It is rough, direct and slightly masculine, and you hear it in anime when a character warns a partner, a rival or an enemy. It sounds natural coming from a battle-hardened hero; it sounds aggressive coming from a stranger on a train.

気きをつけろ! — Watch it! / Be careful! (rough, command form, anime and sports) 足元あしもとに気きをつけろよ。 — Watch your step, you hear? (rough, male, close friends or a senpai) 後うしろ、気きをつけろ! — Watch your back! (rough, shouted in a fight scene)

If you are learning from anime, this is the form most likely to leak into your own speech. Keep it for the screen unless you are talking to very close friends, and use 気きをつけて in real life.

What is the difference between 気きをつけて and 注意ちゅういして?

注意ちゅういして (chuui shite) is a notch more formal and more "instructional". You see 注意ちゅうい on signs and hear it in announcements. It tells you to pay attention to something specific, usually a rule or a hazard, rather than expressing personal care.

足元あしもとに注意ちゅういしてください。 — Please watch your step. (polite, announcements and signs) 頭上ずじょう注意ちゅうい。 — Mind your head. (sign, noun-style, no verb) 以後いご、注意ちゅういしてください。 — Please be careful from now on. (formal, a warning at work)

注意ちゅうい is not what you say to a friend leaving a party. Use it for rules, signs, instructions, and workplace warnings.

How do you say "be careful" in the sense of cautious or thoughtful?

Two other words cover the "cautious" meaning. 用心ようじんして (youjin shite) means to be on guard, and sounds somewhat old-fashioned or like advice from an older relative. 慎重しんちょうに (shinchou ni) means to proceed carefully and thoughtfully, usually with a decision, a plan or a delicate task.

夜道よみちは用心ようじんしてね。 — Be wary on dark roads at night. (casual, slightly old-fashioned, protective) 慎重しんちょうに決きめたほうがいいよ。 — You should decide carefully. (casual, advice about a big choice) 慎重しんちょうに運はこんでください。 — Please carry it carefully. (polite, fragile item)

When English says "carefully" in the sense of "with attention to detail", Japanese often wants 丁寧ていねいに (teinei ni) as well: 丁寧ていねいに書かいてください, "please write neatly and carefully." So "carefully" does not map to one Japanese word. 気きをつけて is for danger and care of the self, 慎重しんちょうに is for caution and judgement, 丁寧ていねいに is for gentle, tidy handling.

How do you tell someone to look after themselves?

無理むりしないで (muri shinai de) means "don't push yourself" and is the kind thing to say to someone who is overworking, running a long journey, or trying to carry on while tired. It is the closest thing to "take care of yourself" when the worry is exhaustion, not an external danger.

無理むりしないでね。 — Don't push yourself, okay? (casual, caring, to a tired friend) あまり無理むりをなさらないでください。 — Please don't overdo it. (very polite, to a senior or a customer) 無理むりするなよ。 — Don't overdo it, man. (rough, male, anime-style concern)

That last one is the sound of a hundred anime episodes: a character with bandages on every limb, and a friend saying 無理むりするなよ in a low voice.

How does the "I'll be careful" reply work?

After an apology or a warning, the usual reply is 気きをつけます (ki wo tsukemasu): "I will be careful." It is a small promise. In a work or formal setting, it follows an apology very often.

気きをつけます。 — I'll be careful. (polite, after being warned or after a mistake) 以後いご、気きをつけます。 — I'll be careful from now on. (formal, standard line after an apology) すみません、気きをつけます。 — Sorry, I'll be careful. (polite, short, everyday workplace)

The full apology toolkit, including how 気きをつけます follows すみません and 申し訳もうしわけありません, is in how to say sorry in Japanese.

For goodbyes, where 気きをつけて sits next to お大事だいじに and いってらっしゃい, see take care in Japanese.

Common mistakes

  • Dropping the に. 車くるまを気きをつけて is wrong; 車くるまに気きをつけて is right. The danger is marked with に, not を.
  • Saying 気きをつけて at the moment of danger. Use 危あぶない! when it is happening now; 気きをつけて is for before and after.
  • Using お大事だいじに for "take care" in general. お大事だいじに is only for someone who is sick or injured. Saying it to a friend leaving for the airport sounds like you think they have a cold. For goodbyes, use 気きをつけて.
  • Using 気きをつけて for every "carefully". 気きをつけて運はこぶ is possible but 慎重しんちょうに運はこぶ or 丁寧ていねいに運はこぶ says what you mean. Think: danger (気きをつけて), caution (慎重しんちょうに), neatness (丁寧ていねいに).
  • Using the command form 気きをつけろ in real life. It is fine in anime and among close male friends. With strangers, colleagues and anyone who is not a close friend it comes across as an order.
  • Forgetting that 気きをつけます is a promise. It is not "please be careful" — it is "I will be careful". Mixing it up with 気きをつけてください flips who is acting.

The "be careful" cheat sheet

Phrase Situation Politeness Example
気きをつけて Goodbye, general warning Casual 気きをつけて帰かえってね。
気きをつけてください / お気きをつけて Goodbye, service, guests Polite お気きをつけてお帰かえりください。
気きをつけろ Fight, sports, anime Rough, command 後うしろ、気きをつけろ!
危あぶない! Immediate danger Any, shouted 危あぶない! 車くるまだ!
注意ちゅういして Signs, rules, workplace Slightly formal 足元あしもとに注意ちゅういしてください。
慎重しんちょうに Decisions, delicate work Neutral 慎重しんちょうに決きめてください。
無理むりしないで Tiredness, illness, overwork Casual 無理むりしないでね。
お大事だいじに Someone sick or injured Polite どうぞお大事だいじに。

For the related meaning "safe and sound", the word 安全あんぜん and the set phrase 無事ぶじ take over.

Practice

Build each answer before opening it. Questions 3 and 4 are a pair about timing, and 5 and 6 are a pair about who is unwell.

1. Say "Watch out for cars" using 気きをつけて.

Show answer

車くるまに気きをつけて — the thing you watch for is marked with に, not を.

2. What is wrong with 足元あしもとを気きをつけてください?

Show answer

を should be に — 足元あしもとに気きをつけてください. The pattern is Noun + に + 気きをつける.

3. A glass slides off a table toward your friend's foot. What do you shout?

Show answer

危あぶない! — it is happening now, so there is no time for 気きをつけて, which is advice for a developing situation.

4. A friend is leaving your house to walk home late at night. What do you say at the door?

Show answer

気きをつけて(帰かえってね) — a farewell with care, said before the danger, not during it. This is the pair to question 3.

5. Your friend is leaving for a flight and is perfectly healthy. Which do you say: 気きをつけて or お大事だいじに?

Show answer

気きをつけて — it is a general "take care" for a journey. お大事だいじに would suggest your friend is ill.

6. A coworker tells you they have a high fever and are heading to the clinic. Which do you say: 気きをつけて or お大事だいじに?

Show answer

お大事だいじに — it is only for someone who is sick or injured. This is the pair to question 5.

7. You see a low beam on a sign in a shop. Which phrase fits the sign: 頭上ずじょう注意ちゅうい or 気きをつけろ?

Show answer

頭上ずじょう注意ちゅうい — signs use the noun-style 注意ちゅうい, which is formal and instructional. 気きをつけろ is a rough spoken command.

8. You want to tell a friend to decide carefully about a big purchase. Which word fits best: 気きをつけて, 慎重しんちょうに, or 丁寧ていねいに?

Show answer

慎重しんちょうに決きめたほうがいいよ — 慎重しんちょうに means careful in judgement. 丁寧ていねいに is for neat, gentle handling of things, and 気きをつけて is for danger.

9. After being warned at work about a mistake, how do you promise to be careful from now on?

Show answer

以後いご、気きをつけます — 気きをつけます states what you will do, so it is a promise; ます keeps it polite: "I will be careful".

10. A tired friend keeps working late. What do you say to show you are worried about them?

Show answer

無理むりしないでね — "don't push yourself" covers exhaustion, which is not an external danger, so 気きをつけて would sound odd.

How you say "be careful" changes with the danger and the person, so in a trial lesson, say it to a friend about to step into traffic, a coworker with a heavy box and a traveller, and compare 危あぶない, 気きをつけて and 注意ちゅういして.

FAQ

Is 気きをつけて the same as "take care"? Mostly yes. It works as a warning and as a farewell, just like "take care". If you only need a goodbye for someone leaving, 気きをつけて is the natural choice, and お気きをつけて is the polite version.

Can I say お大事だいじに instead of 気きをつけて? No. お大事だいじに is only for someone who is sick or injured. Using it as a general goodbye tells the listener you think they are unwell.

What is the difference between 気きをつけて and 気きをつけてください? Politeness. 気きをつけて is casual, between friends and family. 気きをつけてください is the polite request, and お気きをつけて is the smooth, service-style version used by shop staff.

Is 気きをつけろ rude? It is rough and direct. In anime and among close friends it sounds normal and even caring, but with strangers or colleagues it sounds like an order. Use 気きをつけて in everyday speech.

What is "carefully" in Japanese? It depends on the sense. For caution and judgement, use 慎重しんちょうに. For neat, gentle handling, use 丁寧ていねいに. For danger, use 気きをつけて or 注意ちゅういして.

How do I say "be careful" to someone who is sick? Use 無理むりしないでね for "don't push yourself" and お大事だいじに for the standard get-well wish. 気きをつけて alone would sound like a warning about a danger, not a get-well wish.

Vocabulary from this article

Tap the block to select all of it, then copy. In Anki: File → Import, note type Basic, separator Tab, and the two columns land in Front / Back.

気をつける	きをつける — to be careful, to take care
危ない	あぶない — dangerous, watch out
注意する	ちゅういする — to pay attention, to take note
用心する	ようじんする — to be on guard
慎重	しんちょう — careful, cautious
丁寧	ていねい — polite, neat, careful
無理する	むりする — to push oneself
お大事に	おだいじに — get well soon, take care (to the sick)
足元	あしもと — underfoot, one's step
頭上	ずじょう — overhead
以後	いご — from now on

I'm Yuuki, a Japanese teacher based in Tokyo. I've taught on italki as a Top 1% teacher and watched over 1,500 anime, so most of the example sentences on this blog come from lines I've actually heard students ask about — including this one, which comes up in nearly every beginner's first few lessons. For practice with feedback, Book a trial lesson · $13, or work through Japanese practice exercises first.

Sources: the author's own lessons and standard reference grammars.

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