The word「わけ」itself means "reason, logic, cause." The sentence patterns built around it are frequent guests on N3 and N2 exams. This article starts from the basic「わけだ」and works through its four core variations.
Prerequisite: というのは～ことだ
Before diving into「わけだ」, let's cover two patterns that often appear alongside it.
というのは: The definition of... is...
Used to define or explain a noun:
| Example | Meaning |
|---|---|
| 自宅療養とは、自分の家で病気を治すことです。 | "Home care" means treating illness at your own home. |
| アルバイトとは、正式ではない仕事のことです。 | "Arubaito" means a non-regular job. |
ことだ: Giving advice
When「ことだ」follows a verb, it gives advice meaning "you should...":
| Example | Meaning |
|---|---|
| 資格を取りたいなら、もっと時間をかけて勉強することだ。 | If you want to get the qualification, you should spend more time studying. |
| 健康でいたいなら、毎日運動することだ。 | If you want to stay healthy, you should exercise every day. |
わけだ: The Logical Conclusion
「わけだ」expresses an inevitable conclusion derived from known facts. Translates as "no wonder...", "that means...", or "naturally...".
| Example | Meaning |
|---|---|
| 一日百円貯金すれば、一ヶ月で三千円になるわけだ。 | If you save 100 yen a day, that naturally comes to 3,000 yen a month. |
| 彼女は10年もアメリカにいたのか。英語が上手なわけだ。 | She was in America for 10 years? No wonder her English is good. |
Variation 1: わけではない (Not entirely so)
Partial negation. Emphasizes "it's not that it's completely like that," correcting a potential misunderstanding:
| Example | Meaning |
|---|---|
| 勉強したからといって、すぐに活用できるわけではない。 | Just because you studied doesn't mean you can immediately apply it. |
| 嫌いなわけではないが、苦手だ。 | It's not that I dislike it, I'm just not good at it. |
Key: わけではない ≠ complete negation. It's a softer "you can't say it's entirely like that."
Variation 2: わけがない (Absolutely impossible)
Complete negation. The speaker strongly believes something is impossible — "there's no way...":
| Example | Meaning |
|---|---|
| マサは自分の手で作った会社をそんなに簡単に畳むわけがない。 | There's no way Masa would close the company he built with his own hands that easily. |
| あの真面目な人が嘘をつくわけがない。 | There's no way that serious person would lie. |
Compare: Both はずがない and わけがない mean "impossible," but わけがない is more emotional and emphatic.
Variation 3: わけにはいかない (Can't do that)
Expresses being unable to do something due to moral obligations, responsibility, or social pressure. Not "can't" in ability, but "shouldn't/mustn't":
| Example | Meaning |
|---|---|
| みんなは必死だから、私ものんびりしているわけにはいかない。 | Everyone is working desperately, so I can't afford to relax either. |
| 約束した以上、行かないわけにはいかない。 | Since I made a promise, I can't not go. |
Note: The subject of わけにはいかない is usually "I," since only the speaker can feel the external pressure.
Quick Reference
| Pattern | Core meaning | Negation strength | Translation |
|---|---|---|---|
| わけだ | Logical conclusion | — | No wonder / naturally |
| わけではない | Partial negation | Mild | It's not that... |
| わけがない | Impossible | Strong | There's no way... |
| わけにはいかない | Can't do it | External pressure | I can't afford to... |
Summary
- わけだ = inevitable conclusion derived from facts
- わけではない = partial negation, correcting misunderstandings
- わけがない = absolutely impossible (stronger than はずがない)
- わけにはいかない = can't do something due to external pressure
- Related: というのは～ことだ for definitions, ことだ for advice
Practice
1. Fill in the appropriate pattern:
Everyone is studying, so I also ____ relax (のんびりする).
Show answer
のんびりしているわけにはいかない。 Due to external pressure (everyone is working hard), "I can't afford to" relax.
2. What's the difference between「日本語が上手なわけだ」and「日本語が上手なわけではない」?
Show answer
- 上手なわけだ: No wonder their Japanese is good (logical conclusion from some fact)
- 上手なわけではない: It's not that their Japanese is good (correcting a misunderstanding, partial negation)
3. Both わけがない and はずがない mean "impossible" — how do they differ?
Show answer
- わけがない: More emphatic and subjective, carries emotional weight — "There's NO way!"
- はずがない: More objective, based on logical reasoning — "It shouldn't be possible"
- Example: あの人が嘘をつくわけがない (emotional disbelief) vs はずがない (logical deduction)