How to say "careful" in Japanese

• 慎重しんちょうJLPT N3approx.Common
  na-adjective, nounThe general word for careful in the sense of cautious: acting prudently, weighing risks before deciding or acting. It describes a manner of behavior rather than painstaking work, so it fits decisions, negotiations, and dealings with people.
  裁判官さいばんかんには慎重しんちょうさがなくてはならない。↗

  Discretion is proper to judges.
• 入念にゅうねんCommon
  na-adjective, nounCareful in the sense of painstaking: care put into preparation or work so that nothing is overlooked. It describes how a task is done, not a person's character.
  彼かれは入念にゅうねんに書類しょるいを見みた。↗

  He had a good look at the papers.
• 念入りねんいりCommon
  na-adjective, nounCareful as thorough and conscientious: doing a task with close attention to every detail. It overlaps closely with 入念, and both suit work or preparation carried out with deliberate, painstaking care.
  ジョンは、念入ねんいりにその事故じこを調査ちょうさした。↗

  John investigated the accident thoroughly.
• 周到しゅうとうCommon
  na-adjective, nounCareful in the sense of thorough and meticulous planning: thinking everything through in advance so that nothing is overlooked. It applies to plans and preparations rather than to cautious everyday behavior.
  その理論りろんは周到しゅうとうな研究けんきゅうに基もとづいている。↗

  The theory is based on thorough research.
• 用心深いようじんぶかいCommon
  i-adjectiveCareful as a personal trait: wary, watchful, always on guard against danger. It describes a person's disposition rather than the care taken in a task, so it is not the word for painstaking work.
  なるほど彼かれは若わかいが、用よう心深こころふかい。↗

  Indeed he is young, but he is prudent.

Use 慎重 for cautious behavior and decisions, 入念 and 「念入り」 for painstaking care in doing a task, 周到 for thorough advance planning, and 「用心深い」 for a person who is naturally wary and watchful.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 慎重しんちょうcareful
• 入念にゅうねんcareful
• 念入りねんいりcareful
• 周到しゅうとうcareful
• 用心深いようじんぶかいcareful
• 細心さいしんmeticulous
• 綿密めんみつminute
• 丹念たんねんpainstaking
• 克明こくめいdetailed
• 注意深いちゅういぶかいattentive
• きめ細やかきめこまやかattentive to detail
• 深謀しんぼうdeliberate
• 周密しゅうみつscrupulous
• 深甚しんじんprofound (respect, gratitude, etc.)
• 深甚なるしんじんなるprofound (respect, gratitude, etc.)
• そつがないcautious
• そつのないcautious
• 腫れ物に触るようはれものにさわるよう(very) cautious
• 大切たいせつcareful
• 丁寧ていねいcareful
• 緻密ちみつprecise
• 密みつminute
• ご丁寧ごていねいcareful
• 細かいこまかいcareful