“〜hazu ga nai noni・〜nai hazu nanoni”: It Shouldn't Be, Yet [JLPT N1]
Content by NTJ Kuma · Nihongo to Japan editorial team · Updated July 27, 2026
「負けるはずがないのに不安だ」「鍵をかけたはずなのに開いていた」 — logic says one thing, reality does the opposite.
「来るはずがないのに、彼が現れた」 — logically impossible, yet it happened
To express the bewilderment of “it doesn't add up logically, yet it really happened,” 「こんな時間に来るはずがないのに、彼が現れた」 (there's no way he'd come at this hour, yet he appeared) — 「〜はずがないのに・〜ないはずなのに」 = even though it (should)n't ～, yet…, used to express the strong bewilderment/surprise of “logically impossible／shouldn't be so, yet the opposite happened in reality.” This guide covers attachment and separates it from the plain 「はずがない (impossible)」 and 「はずなのに (should be, yet).」
Core: logically impossible, yet it happened in reality
「verb plain form ＋ はずがないのに／ないはずなのに」 means “even though (logically) it's impossible／shouldn't ～, yet (in reality) ～”:
- 鍵をかけたはずなのに、ドアが開いていた (I should have locked it, yet the door was open).
- 間違えるはずがないのに、なぜかミスした (I couldn't possibly get it wrong, yet somehow I made a mistake).
- 彼が知っているはずがないのに、なぜか詳しかった (he couldn't possibly know, yet somehow he was well-informed).
Feel: the core is “logically impossible, yet it happened in reality” — the first half is a “(by reason) impossible／won't-happen judgment,” the second half is “(in reality) it happened, opposite.” It carries the strong bewilderment/surprise of “it shouldn't be so, how could…?” 「〜はずがないのに」 = “it can't possibly ～, yet”; 「〜ないはずなのに」 = “by reason it shouldn't／isn't ～, yet.” It corresponds to “even though it can't possibly ～, yet; even though it shouldn't ～, yet.”
Attachment & forms
| Form | Meaning | Example |
|---|---|---|
| plain form ＋ はずがないのに | it can't possibly ～, yet… | 来るはずがないのに |
| verb ない-form／plain form ＋ ないはずなのに | by reason it shouldn't ～, yet… | 知らないはずなのに |
Examples in use
- そんな高価な物、彼に買えるはずがないのに、プレゼントしてくれた。(Something that expensive, he couldn't possibly afford, yet he gave it to me.)
- 誰もいないはずなのに、二階から物音がした。(There should be no one, yet there was a sound from upstairs.)
- 締め切りに間に合うはずがないのに、彼は平然としている。(There's no way he'll make the deadline, yet he's perfectly calm.)
- 一度も教えていないはずなのに、彼女はもう覚えていた。(I shouldn't have taught it even once, yet she'd already learned it.)
- 効くはずのない薬で、なぜか症状が治まった。(With a drug that shouldn't work, the symptoms somehow subsided.)
⚠️ Where learners slip up
① The core is ‘(by reason) impossible／shouldn't ～, (in reality) yet the opposite' — a logical negation ＋ reality-contradicting bewilderment. 「〜はずがないのに・〜ないはずなのに」 expresses the strong bewilderment/surprise of “by reason judging ‘impossible／won't ～,' yet in reality the opposite happened.” It has two layers: the first half is “(I judge) it can't ～” (a logical negation), and 「のに」 brings out “(in reality) yet ～” (the contradicting fact): 来るはずがないのに、来た (couldn't possibly come, yet came — bewilderment), 知らないはずなのに、知っていた (shouldn't know, yet knew — surprise). Its flavor is “it shouldn't be so, how could…?,” with puzzlement and astonishment. It corresponds to “even though it can't possibly ～, yet; even though it shouldn't ～, yet.” Test: to express “by reason impossible／shouldn't ～, yet the reality is opposite (bewildering)” → はずがないのに／ないはずなのに.
② Attach a verb plain form ＋ はずがないのに／ないはずなのに (＋ the adversative のに). Get the attachment right. Precedes a verb／adjective plain form: 来る→来るはずがないのに, ない→ないはずなのに, 知っている→知っているはずがないのに. It's the combination 「はず（がない）＋のに」 or 「（ない）はず＋なのに,」 the core 「のに／なのに」 being adversative (even though ～, yet…). To modify a noun, 「はずのない ＋ noun」 is also common (効くはずのない薬 = a drug that shouldn't work). Mnemonic: (a by-reason impossible／won't judgment) ＋ のに = even though ～, yet.
③ Division of labor with 「はずがない (plain impossible)」 「はずなのに (should be, yet not).」 These three all have 「はず,」 but differ — don't mix. 「〜はずがないのに」 = it can't possibly ～, yet (reality opposite): with the added 「のに」 adversative and “reality opposite” surprise: 来るはずがないのに、来た (couldn't possibly come, yet came). 「〜はずがない」 = impossible ～, won't ～ (a plain logical negation): it merely asserts “impossible,” without the “yet ～” adversative (see 〈はずがない〉): そんなはずがない (there's no way that's so). 「〜はずなのに」 = by reason it should ～, yet it didn't (opposite direction): the first half is “should ～” (a positive expectation), the second “yet it didn't happen” (see 〈はずなのに〉): 来るはずなのに、来ない (should come, yet didn't). Difference: 「はずがないのに」 = by reason ‘impossible' ～, yet it happened (a negative expectation defied); 「はずなのに」 = by reason ‘should' ～, yet it didn't happen (a positive expectation defied); 「はずがない」 = plain ‘impossible' (no adversative). Test: “by reason impossible ～, yet it happened” → はずがないのに; “by reason should ～, yet it didn't” → はずなのに (see 〈はずなのに〉); a plain “impossible” → はずがない (see 〈はずがない〉).
🔄 Compare with similar forms: はずがないのに／はずがない／はずなのに／わけがないのに
| Form | Emphasis | Example |
|---|---|---|
| 〜はずがないのに | it can't possibly ～, yet (a negative expectation defied, bewilderment) | 来るはずがないのに |
| 〜はずがない | impossible ～, won't ～ (a plain logical negation) | 来るはずがない （there's no way they'd come） |
| 〜はずなのに | it should ～, yet (a positive expectation defied) | 来るはずなのに |
| 〜わけがないのに | it can't possibly ～, yet (≒はずがないのに, more colloquial) | 分かるわけがないのに |
💡 The one thing to remember
「〜はずがないのに・〜ないはずなのに」 = even though it (should)n't ～, yet… — three points: ① the core is “(by reason) impossible／shouldn't ～, (in reality) yet the opposite” — a logical negation ＋ reality-contradicting strong bewilderment (来るはずがないのに、来た); ② attach a verb plain form ＋ はずがないのに／ないはずなのに, the core 「のに」 being adversative; ③ division of labor with 「はずがない (plain impossible, see 〈はずがない〉)／はずなのに (should be yet not, see 〈はずなのに〉).」 — this is “impossible yet happened,” はずなのに is “should yet didn't.” This pattern suits that “doesn't add up logically, yet truly happened” astonishment — “it was impossible, yet he did it,” “I locked it, yet it's open.” To write that “how could this be?” bewilderment, 「〜はずがないのに」 is most vivid.
❓ Common questions
Q: What's the difference between 「来るはずがないのに」 and 「来るはずなのに」? Just the 「が」?
One 「が」 apart, but opposite meanings — one is “by reason ‘impossible' to come, yet came,” one is “by reason ‘should' come, yet didn't.” 「〜はずがないのに」 = by reason ‘impossible' ～, yet (the opposite happened in reality): 「はずがない」 = “impossible, won't” (a negative judgment), plus 「のに」 = “even though impossible, yet ～”: 来るはずがないのに、（実際に）来た (couldn't possibly come, yet came — I judged “won't come,” result “came,” a negative expectation defied). It's “by reason impossible → yet it happened.” 「〜はずなのに」 = by reason ‘should' ～, yet (it didn't happen): 「はず（な）」 = “should, ought to” (a positive expectation), plus 「のに」 = “even though should, yet didn't ～”: 来るはずなのに、（実際は）来ない (should come, yet doesn't — I judged “should come,” result “didn't,” a positive expectation defied) (see 〈はずなのに〉). Difference: 「はずがないのに」 = by reason ‘impossible' ～, yet it happened (a negative expectation defied); 「はずなのに」 = by reason ‘should' ～, yet it didn't (a positive expectation defied). One is “what shouldn't happen happened,” one is “what should happen didn't” — opposite directions. Test: check whether there's 「が（ない）」 after 「はず」 — 「はずがない（のに）」 = impossible (yet…); 「はず（なのに）」 = should (yet…). So 「来るはずがないのに来た (couldn't come yet came)」 vs 「来るはずなのに来ない (should come yet doesn't)」 — one 「が」 apart, one is “the impossible happened,” one is “the expected didn't.”
Q: What's the difference between 「はずがないのに」 and 「はずがない」?
The difference is whether there's the 「のに (yet)」 adversative and the “reality opposite” surprise. 「〜はずがない」 = impossible ～, won't ～ (a plain logical negation, an assertion): it merely asserts “by reason impossible／won't ～,” a conclusion, without “but reality is opposite”: そんなこと、あるはずがない (there's no way that exists — plain assertion of “impossible”), 彼が嘘をつくはずがない (he couldn't possibly lie — I'm sure he wouldn't) (see 〈はずがない〉). It stops at the “impossible” judgment. 「〜はずがないのに」 = it can't possibly ～, yet (the opposite happened in reality): it adds 「のに」 after 「はずがない,」 bringing out the adversative and surprise of “yet it did happen in reality”: 彼が嘘をつくはずがないのに、（実際は）嘘をついていた (he couldn't possibly lie, yet he really did — I thought he wouldn't, result he did, surprising). Its point is the bewilderment of “by reason impossible, yet reality opposite.” Difference: 「はずがない」 is “(assert) impossible ～” (a conclusion, stops there); 「はずがないのに」 is “even though impossible ～, yet it happened” (＋ adversative ＋ reality-opposite surprise). Test: to merely assert “impossible ～” → はずがない (see 〈はずがない〉); to express “even though impossible ～, yet reality opposite (surprising)” → はずがないのに. E.g. 「彼が犯人のはずがない (he can't be the culprit — assertion)」 uses はずがない; 「彼が犯人のはずがないのに、証拠が出てきた (he can't be the culprit, yet evidence emerged — surprise)」 uses はずがないのに. The former is an assertion, the latter “an assertion ＋ the bewilderment of it being overturned.”
🖊️ Practice Quiz
Q1. 「あんなに練習したのだから、負ける___。」(there's no way I'd lose, yet …)
(A) はずがないのに (B) に違いない (C) おそれがある (D) かもしれない
Q2. What does 「ないはずなのに」 mean?
(A) by reason it shouldn't be so, yet (adversative)
(B) it definitely will
(C) no adversative
(D) a command
Q3. What does 「来るはずがないのに待つ」 mean?
(A) waiting even though there's no way he'd come
(B) he'll definitely come
(C) not waiting for him
(D) he came
Q4. What is the latter clause of 「はずがないのに」?
(A) a fact contrary to the inference (with surprise/doubt)
(B) a command
(C) pure time
(D) a wish
Q5. Which connection is correct?
(A) 知っているはずなのに、黙っている。
(B) 知るはずがないのにを。
(C) 知っていはずなのに。
(D) 知るはずがないのにだ。
Answer Key
1. (A) はずがないのに ── there's no way I'd lose, yet (feeling uneasy).
2. (A) ── by reason it shouldn't be so, yet (adversative).
3. (A) ── waiting even though there's no way he'd come.
4. (A) ── a fact contrary to the inference (with surprise/doubt).
5. (A) 知っているはずなのに、黙っている ── should know, yet stays silent (correct connection).