“〜hazu nanoni / 〜hazu datta noni”: Should Have, Yet… [JLPT N4]
By Nihongo to Japan · Updated July 3, 2026
A strong expression of regret when an expectation falls through.
“〜hazu nanoni / 〜hazu datta noni”: Should Have, Yet…
「(plain form) ＋ はずなのに」「〜はずだったのに」 expresses ‘by reason it should be 〜, yet (unexpectedly) it isn't' — the surprise/disappointment of a fallen-through expectation. ① はずなのに = it should (now) be 〜, yet (彼は来るはずなのに、まだ来ない = he should be coming, yet he's not here); ② はずだったのに = it should have been 〜, yet (a past expectation falling through: 約束したはずだったのに = we'd agreed, yet…). ⚠️ Connection: verb/い-adjective plain form ＋ はず; noun ＋ の ＋ はず (学生のはず); な-adjective ＋ な ＋ はず (静かなはず)! ⚠️ Contrast with 「はずだ (ought to be)」: はずなのに carries an adversative, disappointed tone of ‘yet it isn't so.' ⚠️ Don't confuse with 「べき (should do, obligation)」 — はず is the inference ‘it ought to be so,' べき is the obligation ‘ought to do.'
🧠 Core nuance: a grounded expectation has fallen through, with surprise and disappointment
The core is based on some grounds one thinks ‘it ought to be so,' but the result is the opposite, expressing the surprise/disappointment of a fallen-through expectation: 「はず」 itself means ‘by reason/by plan it should be 〜' (a grounded inference); adding 「〜なのに (even though … yet)」 makes 「はずなのに = it should be 〜, yet (surprisingly) it isn't,」 carrying ‘I didn't expect this, how disappointing' (彼は来るはずなのに、まだ来ない = he ought to be coming, yet he's not here; このボタンを押せば開くはずなのに、開かない = pressing this should open it, yet it doesn't). ① 〜はずなのに — a present expectation falls through (合格できるはずなのに自信がない); ② 〜はずだったのに — a past expectation falls through (‘it should have been 〜' but didn't happen: 約束したはずだったのに来なかった = we'd agreed, yet he didn't come). ⚠️ Important connection: verb・い-adjective plain form attaches to はず directly (来るはず, 高いはず); noun ＋ の ＋ はず (学生のはず, ✗ 学生はず); な-adjective ＋ な ＋ はず (静かなはず, ✗ 静かだはず)! ⚠️ Contrast with 「はずだ (ought to, should)」: a plain inference; 「はずなのに」 adds an adversative, stressing the disappointment of ‘yet it isn't so.' ⚠️ Don't confuse with 「べき (should do, obligation/advice)」: はず = inference ‘it ought to be so,' べき = obligation ‘ought to do.' An N4 pattern for a fallen-through expectation.
📌 Connection Rules
| Part of speech | Connection | Example |
|---|---|---|
| verb | plain form ＋ はず | 来るはずなのに |
| い-adjective | plain form ＋ はず | 高いはずなのに |
| noun | ＋ の ＋ はず | 学生のはずなのに |
| な-adjective | ＋ な ＋ はず | 静かなはずなのに |
| past expectation | 〜はずだったのに | 約束したはずだったのに |
💬 Example Sentences
- 彼は来るはずなのに、まだ来ない。(He should be coming, yet he's not here.) — present expectation falls through
- このボタンを押せば開くはずなのに、開かない。(Pressing this button should open it, yet it doesn't.) — expectation falls through
- 試験に合格できるはずなのに、なぜか自信がない。(I should be able to pass, yet for some reason I lack confidence.) — expectation falls through
- 約束したはずだったのに、彼は来なかった。(We'd agreed, yet he didn't come.) — past expectation falls through
- 彼は学生のはずなのに、まるで先生のようだ。(He should be a student, yet he's just like a teacher.) — noun の ＋ はず
🔄 Compare: はずなのに vs はずだ vs べき vs のに
| Expression | Nuance | Example |
|---|---|---|
| 〜はずなのに | should be 〜, yet (expectation falls through) | 来るはずなのに来ない |
| 〜はずだ | ought to, should (inference) | 来るはずだ |
| 〜べき | ought to do (obligation/advice) | 行くべきだ |
| 〜のに | even though 〜, yet (adversative, regret) | 高いのに買った |
⚠️ Common Mistakes
- Connection: noun ＋ の ＋ はず (学生のはず, ✗ 学生はず); な-adjective ＋ な ＋ はず (静かなはず, ✗ 静かだはず)!
- はず vs べき: はず = inference ‘it ought to be so'; べき = obligation ‘ought to do' — don't confuse.
- Past expectation uses はずだったのに: it should have been 〜 but didn't happen (約束したはずだったのに).
- はずなのに carries disappointment: it stresses the fallen-through expectation of ‘yet it isn't so,' adding adversative emotion to a plain はずだ.
💡 Nuance & When to Use
「〜はずなのに/〜はずだったのに」 expresses a fallen-through expectation: based on grounds one thinks it ought to be so, but the result is the opposite, with surprise and disappointment (来るはずなのに来ない, 約束したはずだったのに). ⚠️ Connection: verb/い-adj plain form ＋ はず, noun ＋ の ＋ はず, な-adjective ＋ な ＋ はず! Contrast with はずだ (plain inference), べき (obligation). An N4 fallen-expectation pattern — memorize it.
🎯 JLPT Exam Tips
- N4 core: 〜はずなのに = should be 〜, yet (expectation falls through); 〜はずだったのに = should have been 〜, yet (past expectation falls through).
- Connection: verb/い-adj plain form ＋ はず; noun ＋ の ＋ はず; な-adjective ＋ な ＋ はず (✗ 学生はず, ✗ 静かだはず).
- Distinction: はず (inference ‘ought to be so') vs べき (obligation ‘ought to do'); はずなのに carries the disappointment of ‘yet it isn't.'
🖊️ Practice Quiz
Q1. 「試験に合格できる___なのに、なぜか自信がない。」(should be able to pass) Which is correct?
(A) はず (B) べき (C) よう (D) そう
Q2. 「彼は学生___はずなのに、まるで先生のようだ。」(noun ＋ はず) Fill the blank.
(A) な (B) の (C) だ (D) と
Q3. 「このボタンを押せば開く___、開かない。」(should open) Which is correct?
(A) ようなのに (B) はずなのに (C) そうなのに (D) べきなのに
Q4. 「約束した___なのに、彼は来なかった。」(we'd agreed — past expectation fell through) Which is correct?
(A) はず (B) はずだった (C) べき (D) そう
Q5. 「この店は静か___はずなのに、今日はうるさい。」(な-adjective 静か ＋ はず) Fill the blank.
(A) の (B) だ (C) な (D) で
Answer Key
1. (A) はず ── はずなのに = should …, yet (expectation falls through). (B) べき = obligation; (C)(D) don't fit.
2. (B) の ── a noun ＋ の ＋ はず: 学生のはず (✗ 学生はず).
3. (B) はずなのに ── a verb plain form ＋ はずなのに: 開くはずなのに = should open, yet doesn't.
4. (B) はずだった ── 「はずだったのに」 = should have …, yet (past expectation): 約束したはずだったのに.
5. (C) な ── a な-adjective ＋ な ＋ はず: 静かなはず (✗ 静かだはず).