“〜naze ka・〜dou iu wake ka”: For Some Reason [JLPT N2]
By Nihongo to Japan · Updated July 3, 2026
An exclamation that the cause is unknown but the result is indeed so.
“〜naze ka・〜dou iu wake ka”: For Some Reason
「なぜか」 and 「どういうわけか」 are adverbs meaning “for some reason, somehow” — the result is indeed so, but no clear cause can be given, with a touch of puzzlement or wonder. E.g. 「なぜか、今日はやる気が出ない」 (for some reason, I have no motivation today), 「どういうわけか、彼だけ呼ばれなかった」 (for some reason, only he wasn't called). Placed at the head or mid-sentence, it adds a ‘cause unknown' color to the fact that follows.
🧠 Core nuance: there's this result, but even you can't say why
The core is the result exists, but the cause is unknown, hard to explain: something did happen (no motivation, tears, only he wasn't called), but even the speaker can't give a clear reason, with puzzlement or wonder. 「なぜか」 (for some reason) comes from 「なぜ (why) ＋ か」; 「どういうわけか」 (for some unknown reason) from 「どういうわけ (what reason) ＋ か」; the two are nearly identical, with どういうわけか slightly stressing ‘a reason one can't figure out.' ⚠️ It's not a question (✗ no reason follows), but a statement that ‘the cause is unknown but the result is so.' Entirely different from the reason-giving 「なぜなら (because)」.
📌 How to Connect
| Form | Use | Example |
|---|---|---|
| なぜか ＋ (fact) | for some reason 〜 | なぜかやる気が出ない |
| どういうわけか ＋ (fact) | for some unknown reason 〜 | どういうわけか呼ばれなかった |
| (at head or mid-sentence) | modifies the following clause | 今日はなぜか眠い |
💬 Example Sentences
- なぜか、今日は朝からやる気が出ない。(For some reason, I've had no motivation since this morning.) — cause unknown
- 映画を見ていたら、なぜか涙が出てきた。(While watching the movie, for some reason tears came.) — wonder
- どういうわけか、その日は彼だけ呼ばれなかった。(For some reason, only he wasn't called that day.) — can't figure out
- どういうわけか、急に部屋が静かになった。(For some reason, the room suddenly went quiet.) — puzzlement
- 理由は分からないが、なぜか彼のことが気になる。(I don't know why, but for some reason I'm concerned about him.) — can't say why
🔄 Compare: なぜか vs なぜなら vs どうも vs どうせ
| Expression | Nuance | Example |
|---|---|---|
| なぜか/どういうわけか | “for some reason” (cause unknown but result is so) | なぜか涙が出た |
| なぜなら | “because” (giving a reason, followed by the cause) | なぜなら〜からだ |
| どうも | “somehow, can't quite say why” (vague feeling, near なぜか) | どうも調子が悪い |
| どうせ | “anyway, in any case” (resigned assertion) | どうせ無理だ |
⚠️ Common Mistakes
- Confusing with なぜなら: なぜか = for some reason (cause unknown); なぜなら = because (giving a reason, followed by the cause) — opposite!
- A reason following: なぜか states the cause is unknown; it isn't followed by ‘because….'
- As a question: なぜか isn't a question (✗ なぜか?), but a ‘for some reason' statement.
- なぜか ≒ どういうわけか: nearly identical, interchangeable.
💡 Nuance & When to Use
なぜか・どういうわけか mean “for some reason, somehow” — the result is indeed so, but no clear cause can be given, with puzzlement or wonder (for some reason no motivation, for some reason tears, for some reason only he wasn't called). Placed at the head or mid-sentence, it adds a ‘cause unknown' color to the following fact. ⚠️ Entirely opposite to the reason-giving 「なぜなら (because, followed by a reason)」 — don't confuse. Close to the vague-feeling どうも. A must at N2.
🎯 JLPT Exam Tips
- High-frequency N2: なぜか/どういうわけか = for some reason (cause unknown but result indeed so); at head or mid-sentence.
- Core distinction: なぜか (for some reason, cause unknown) vs なぜなら (because, followed by a reason) — opposite!
- Near-synonym: どうも (somehow, can't quite say why) is close to なぜか.
🖊️ 練習題（5題）
Q1. 「___、今日はやる気が出ない。」（不知為何沒幹勁）
(A) なぜか (B) なぜなら (C) どうせ (D) せっかく
Q2. 「___、彼だけ呼ばれなかった。」（不知什麼緣故）
(A) どういうわけか (B) どうしても (C) どうせ (D) どうやって
Q3. 「なぜか涙が出た」の意味は?
(A) 不知為何流下了淚
(B) 因為某明確原因哭
(C) 故意哭
(D) 沒有哭
Q4. 「なぜか」の語感は?
(A) 不知為何（有結果但說不出原因，帶疑惑）
(B) 因為有明確原因
(C) 命令
(D) 禮貌請求
Q5. 用法が自然なのは?
(A) どういうわけか、急に静かになった。 (B) なぜか、理由は3つある。
(C) なぜかなぜなら。 (D) なぜか必ず行く。
答案解析
1. (A) なぜか ── 不知為何沒幹勁。
2. (A) どういうわけか ── 不知什麼緣故。
3. (A) ── 不知為何流淚。
4. (A) ── 有結果但說不出原因。
5. (A) ── 「どういうわけか急に静かに」自然;(B)有明確原因矛盾。