Quadruple VS
Synonym Boundary: "訳", "理性", "いわく", "理"
All represent the core concept "reason", but require precise selection.
Japanese Option A
訳
わけ (wake)
N3 / CEFR
Japanese Option B
理性
りせい (risei)
N3 / CEFR
Japanese Option C
いわく
いわく (iwaku)
N2 / CEFR
Japanese Option D
理
ことわり
C2PLUS / CEFR
Quadruple VS Nuance Contrast & Social Differences
When expressing "reason" in Japanese, you must carefully distinguish between "訳", "理性", "いわく", "理" based on context.
- 訳 (わけ (wake) - Level: N3): Maps to "reason; cause; meaning; circumstances; result" and is used when Explains the reason or circumstances behind something. Often used in phrases like 「〜わけだ」.
- 理性 (りせい (risei) - Level: N3): Maps to "reason; intellect; self-control; sanity; rational mind" and is used when Refers to reason, intellect, self-control, sanity, or the rational mind that suppresses emotional impulses to make logical and moral decisions. Often used as 理性を失う.
- いわく (いわく (iwaku) - Level: N2): Maps to "reason, cause, history, legend (often with a negative connotation or mystery)" and is used when Often used to introduce something mysterious, suspicious, or with a specific backstory. Can also mean 'according to...' when quoting someone, often with skepticism..
- 理 (ことわり - Level: C2PLUS): Maps to "reason; principle; logic; truth (classical usage)" and is used when Essential structural term in CEFR C2PLUS vocabulary syllabus..
Context for "訳"
彼が遅れたのは電車が遅れた訳です。
The reason he was late was that the train was delayed.
Context for "理性"
激しい怒りを感じたとしても、感情のままに行動せず、_______を保って冷静に対処することが求められます。
Even if one feels intense anger, they are required to maintain reason and handle it calmly without acting on emotion.
Context for "いわく"
その屋敷にはいわくがあると言われている。
It is said that there is a story/mystery behind that mansion.
Context for "理"
私は理に興味があります。
I am interested in reason; principle; logic; truth (classical usage).
Synonym Mastery Challenge
Which Japanese word perfectly fits this blank space?
Fill in the blank: "彼が遅れたのは電車が遅れた ＿＿＿ です。" (Meaning: "The reason he was late was that the train was delayed.")
🎉 Correct Answer!
Remember: "訳" is correct here because it represents "reason; cause; meaning; circumstances; result" in the context: "The reason he was late was that the train was delayed.".