Quintuple VS
Synonym Boundary: "理由", "訳", "わけ", "いわく", "所以"
All represent the core concept "reason", but require precise selection.
Japanese Option A
理由
りゆう (riyū)
N4 / CEFR
Japanese Option B
訳
わけ (wake)
N3 / CEFR
Japanese Option C
わけ
わけ (wake)
N3 / CEFR
Japanese Option D
いわく
いわく (iwaku)
N2 / CEFR
Japanese Option E
所以
ゆえん (yuen)
N1 / CEFR
Quintuple VS Nuance Contrast & Social Differences
When expressing "reason" in Japanese, you must carefully distinguish between "理由", "訳", "わけ", "いわく", "所以" based on context.
- 理由 (りゆう (riyū) - Level: N4): Maps to "reason, motive" and is used when A noun referring to the cause or explanation for something. Often used with なぜ.
- 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」.
- 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.
- 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'..
Context for "理由"
遅刻した理由を教えてください。
Please tell me the reason for being late.
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 "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 "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.
Synonym Mastery Challenge
Which Japanese word perfectly fits this blank space?
Fill in the blank: "遅刻した ＿＿＿ を教えてください。" (Meaning: "Please tell me the reason for being late.")
🎉 Correct Answer!
Remember: "理由" is correct here because it represents "reason, motive" in the context: "Please tell me the reason for being late.".