Quintuple VS
Synonym Boundary: "わけ", "理性", "いわく", "所以", "理"
All represent the core concept "reason", but require precise selection.
Japanese Option A
わけ
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
所以
ゆえん (yuen)
N1 / CEFR
Japanese Option E
理
ことわり
C2PLUS / CEFR
Quintuple VS Nuance Contrast & Social Differences
When expressing "reason" in Japanese, you must carefully distinguish between "わけ", "理性", "いわく", "所以", "理" based on context.
- わけ (わけ (wake) - Level: N3): Maps to "reason, circumstances, meaning" and is used when A versatile word implying 'reason', 'circumstance', or 'natural conclusion'. Often used in grammatical patterns 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..
- 所以 (ゆえん (yuen) - Level: N1): Maps to "reason; cause; origin; source; the reason why..." and is used when A formal and somewhat literary term. Often used in the pattern 「〜の所以」 or 「〜する所以」 to explain the fundamental reason, origin, or essence of something, implying 'the very reason why something is as it is'..
- 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 "わけ"
毎日運動しているから、体が健康なわけだ。
Because I exercise every day, it means my body is healthy (it's natural that my body is healthy).
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 "所以"
彼が成功した所以は、たゆまぬ努力にあった。
The reason he succeeded was his tireless effort.
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: "毎日運動しているから、体が健康な ＿＿＿ だ。" (Meaning: "Because I exercise every day, it means my body is healthy (it's natural that my body is healthy).")
🎉 Correct Answer!
Remember: "わけ" is correct here because it represents "reason, circumstances, meaning" in the context: "Because I exercise every day, it means my body is healthy (it's natural that my body is healthy).".