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Quadruple VS

Synonym Boundary: "きめる", "決める", "決心する", "〜ことにする"

All represent the core concept "decide", but require precise selection.

Japanese Option A

きめる

きめる (kimeru)
N5 / CEFR
Japanese Option B

決める

きめる (kimeru)
N4 / CEFR
Japanese Option C

決心する

けっしんする (kesshinsuru)
N3 / CEFR
Japanese Option D

〜ことにする

〜ことにする (〜koto ni suru)
N3 / CEFR

Quadruple VS Nuance Contrast & Social Differences

When expressing "decide" in Japanese, you must carefully distinguish between "きめる", "決める", "決心する", "〜ことにする" based on context.
  • きめる (きめる (kimeru) - Level: N5): Maps to "to decide" and is used when Transitive verb meaning 'to decide' or 'to fix'. Often used for plans, rules, or choices. The intransitive form is 決まる.
  • 決める (きめる (kimeru) - Level: N4): Maps to "to decide" and is used when Transitive verb. Used for making a decision, setting a plan, or determining something. Can also mean to fix or settle..
  • 決心する (けっしんする (kesshinsuru) - Level: N3): Maps to "to decide, to make up one's mind, to resolve" and is used when Implies a firm, strong decision or resolution, often made after careful thought or overcoming hesitation. It is a する-verb..
  • 〜ことにする (〜ことにする (〜koto ni suru) - Level: N3): Maps to "to decide to, to make a point of, to choose to" and is used when Expresses a personal decision or resolution made by the speaker. It's about 'making it a rule' or 'deciding' to do something. Contrast with 「〜ことになる」which implies a decision made by others or circumstances..
Mixing these up can easily lead to unnatural translations. Refer to the bilingual context cards below to master the boundaries!
Context for "きめる"
来週の旅行の予定を決めました。
I decided the schedule for next week's trip.
Context for "決める"
来週の旅行の予定を決めました。
I decided on the travel plans for next week.
Context for "決心する"
彼は留学する決心をした。
He decided to study abroad.
Context for "〜ことにする"
明日から毎日運動することにした。
I decided to exercise every day from tomorrow.

Synonym Mastery Challenge

Which Japanese word perfectly fits this blank space?

Fill in the blank: "来週の旅行の予定を決めました。" (Meaning: "I decided the schedule for next week's trip.")
🎉 Correct Answer!

Remember: "きめる" is correct here because it represents "to decide" in the context: "I decided the schedule for next week's trip.".

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