“〜naze ka・〜dou iu wake ka”: For Some Reason [JLPT N2]

Content by NTJ Kuma · Nihongo to Japan editorial team · Updated July 27, 2026

「なぜか涙が出てきた」 — the result is real, but you can't say why.

「なぜか涙が出てきた」 — can't say why, yet somehow so

Listening to an old song, 「なぜか涙が出てきた」 (for some reason the tears came) — 「なぜか・どういうわけか」 = for some reason, somehow, used to say “can't put a finger on the cause, but the result is definitely so.” It's not asking “why”; it states a cause-unknown reflection. This guide covers 「なぜか」's use and distinguishes it from the true question 「なぜ」 and the vague-feeling 「なんとなく.」

Core: なぜか = cause unknown, but the result is definitely so

「なぜか」 is 「なぜ (why) ＋ か (uncertainty),」 literally “not knowing why,” used to express “I can't say the cause, but the thing/feeling is just so”:

• なぜか = for some reason, somehow: なぜか彼のことが気になる (somehow I keep thinking about him), なぜか今日はうまくいった (for some reason today went well).
• どういうわけか = somehow, for some reason (synonym, stressing puzzlement): どういうわけか、彼女は来なかった (for some reason, she didn't come).

Feel: “for some reason ～, somehow ～” — the core is “the result is certain (it definitely happened/there's definitely this feeling), but the cause is unknown.” Often with surprise, puzzlement, reflection, followed by that “cause-unclear” fact or feeling.

How it attaches

See it in context

• なぜか、初めて会った気がしない。(For some reason, it doesn't feel like a first meeting.)
• どういうわけか、鍵が見つからない。(Somehow, I can't find my keys.)
• 理由はないが、なぜか胸騒ぎがする。(No reason, yet somehow I have a bad feeling.)
• なぜか今日に限って、電車が空いている。(For some reason, of all days today, the train is empty.)
• なぜか彼の言葉だけは、今も覚えている。(For some reason, his words alone I still remember.)

⚠️ Easy traps to avoid

① 「なぜか」 isn't the question ‘why'; it states ‘for some reason.' The biggest trap is taking 「なぜか」 as a question. 「なぜ (＝どうして)」 = why (interrogative): なぜ来なかったの？ (why didn't you come?) — this asks the cause. 「なぜか」 = for some reason (declarative): なぜか来なかった (for some reason [he] didn't come) — this states a cause-unknown fact, not a question. The difference is that 「か」: adding 「か」 makes it “(not knowing) why ＋ か (uncertain)” = “can't say why.” So 「なぜか」 is followed by a period-ending statement (安心した, 涙が出た), not a question mark.

② The difference from 「なんとなく」: a certain result vs a vague feeling. Both carry “can't say the cause,” but the emphasis differs. 「なぜか」 = there's a clear result/fact, but the cause is unknown: なぜか涙が出た (for some reason [I definitely] cried — the crying is certain, only the cause is unknown). 「なんとなく」 = even the feeling itself is vague, involuntary: なんとなく嫌な予感がする (I somehow have a bad feeling — even the “feeling” is faint and hard to pin down). Simply: 「なぜか」 stresses “cause unknown” (result clear); 「なんとなく」 stresses “faint, groundless feeling” (even the feeling vague). 「なぜか成功した」 (somehow succeeded — success is fact) vs 「なんとなく選んだ」 (picked without particular reason — the action casual).

③ What follows is usually an ‘unexpected, involuntary, emotional' result. What 「なぜか」 most often pairs with are results or feelings that even the speaker finds unexpected, beyond rational explanation: なぜか涙が出る (inexplicably tear up), なぜか気になる (inexplicably mind it), なぜか安心する (inexplicably feel at ease), なぜかうまくいった (somehow it just worked out). It rarely attaches to a “because A, therefore B” sentence with a clear cause — precisely because if the cause is clear, you wouldn't use 「なぜか.」 So after 「なぜか」 there's usually a slightly magical, puzzling, emotional result — that's where its flavor lies.

🔄 Compare: なぜか／なんとなく／どういうわけか／なぜ (question)

💡 Learning tip

「なぜか」 is a flavorful adverb = “for some reason, somehow” — three points: ① it's a statement, not a question — 「なぜ (why)」 is a question, while the 「か」-added 「なぜか」 is the statement “(I) can't say why,” followed by a period-ending fact/feeling (なぜか涙が出た), not a question mark; ② tell it apart from 「なんとなく」 — 「なぜか」 is “result certain, cause unknown,” 「なんとなく」 is “even the feeling faint, going by feel”; ③ what follows is mostly an unexpected, emotional, inexplicable result (inexplicably mind it, inexplicably tear up, somehow succeeded). 「どういうわけか」 is its synonym partner, stressing “can't figure out what happened.” This word especially suits depicting feelings and coincidences that reason can't explain yet truly exist — なぜか、この曲を聴くと故郷を思い出す (for some reason, hearing this tune brings back my hometown) — with a fine literary sensibility.

❓ Common questions

Q: 「なぜか」 and 「なぜ」 differ by just one 「か」 — is the meaning very different?

Very different — one is a statement, the other a question. 「なぜ (＝どうして)」 = why (interrogative), used to ask the cause, usually followed by a question: なぜ遅刻したの？ (why were you late?), なぜ空は青いのか (why is the sky blue). 「なぜか」 = for some reason (declarative), the added 「か」 marking “uncertain, unknown,” the whole becoming “(even I myself) don't know why, but …,” followed by a declarative sentence (fact or feeling), not a question: なぜか遅刻してしまった (somehow I ended up late), なぜか空が青く見える (for some reason the sky looks especially blue). In one line: 「なぜ」 asks “why?” (expecting the cause in reply); 「なぜか」 says “for some reason, anyway just …” (unable to give the cause oneself, merely stating the result). So 「なぜ来ないの？」 asks “why won't you come,” while 「なぜか来なかった」 says “[he] for some reason didn't come” — one question mark, one period, entirely different contexts. This “question word ＋ か = uncertain statement” rule also applies to other question words: いつか (someday), どこか (somewhere), 誰か (someone), 何か (something) — all “question word ＋ か” becoming “some uncertain ～.”

Q: 「なぜか」 and 「なんとなく」 both mean ‘somehow' — how do I tell them apart?

The difference is “cause unknown” vs “feeling vague.” 「なぜか」 = there's a clear result/fact, only the cause is unknown: the result is clear, certain, and what's unsayable is only “why it's so.” なぜか涙が出た (for some reason I cried — the “crying” is beyond doubt, only the cause unclear), なぜか彼が気になる (inexplicably mind him — the “minding” is a certain feeling, only the why unsayable). 「なんとなく」 = involuntarily, by feel, with even that feeling/judgment itself faint and vague: なんとなく選んだ (picked without particular reason, casually — the action itself offhand), なんとなく嫌な感じ (somehow a bit off — even the “off” is a faint intuition). In brief: 「なぜか」 focuses on “result certain ＋ cause a mystery” (stressing puzzlement); 「なんとなく」 focuses on “faint, groundless, by intuition” (stressing vagueness). Sometimes the two are interchangeable (なぜか／なんとなく 気になる), but the feel differs: 「なぜか気になる」 leans “I really mind it, but can't fathom why” (a bit surprised at one's own minding); 「なんとなく気になる」 leans “faintly, vaguely mind it” (the minding itself faint). To stress the puzzlement of “there's a result yet no findable cause,” 「なぜか」 fits best.

🖊️ Practice Questions (5)

Q1. 「___、今日はやる気が出ない。」(for some reason, no motivation)

(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。」(for some unknown reason)

(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. What does 「なぜか涙が出た」 mean?

(A) For some reason, tears fell

(B) Cried for a clear reason

(C) Cried on purpose

(D) Didn't cry

Q4. What is the nuance of 「なぜか」?

(A) For some reason (there is a result but the cause can't be stated, with a sense of puzzlement)

(B) Because there is a clear reason

(C) A command

(D) A polite request

Q5. Which usage is natural?

(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。

Answer Explanations

1. (A) なぜか ── For some reason, no motivation.

2. (A) どういうわけか ── For some unknown reason.

3. (A) ── For some reason, tears fell.

4. (A) ── There is a result but the cause can't be stated.

5. (A) ── 「どういうわけか急に静かに」 is natural; (B) contradicts by giving a clear reason.