“〜tsui・〜tsui ni”: Unintentionally vs At Last (one character apart, totally different) [JLPT N2]
By Nihongo to Japan · Updated July 3, 2026
Habitual unconscious actions versus a result after long waiting.
“〜tsui・〜tsui ni”: Unintentionally vs At Last
This pair of adverbs differs by just one 「に」, but means entirely different things: つい = “unintentionally, can't help it, before you know it” (an unconscious, habitual action, often with regret): 「ダメだと分かっていても、つい甘い物に手が出る」 (even knowing it's bad, I can't help reaching for sweets), 「つい食べ過ぎた」 (I ended up overeating); ついに = “at last, finally” (a result after a long time): 「長い闘病の末、ついに回復した」 (after a long illness, he finally recovered). One is ‘unintentionally,' the other ‘at last' — don't mix!
🧠 Core nuance: つい = can't help it; ついに = the final result after a long time
The core is two entirely different meanings: ① つい — doing something unconsciously, can't help it, by accident (often something you shouldn't, or habitual), often with regret or resignation (つい食べ過ぎた = ended up overeating, つい言ってしまった = blurted it out); ② ついに — the final result after a long time and great effort, “at last…” (often a major, long-awaited result: ついに完成した, ついに優勝した). ⚠️ Just one 「に」 apart, worlds of difference: つい = unintentionally (by accident); ついに = at last (final result). Don't confuse with 「ついでに (while at it), ついては (therefore)」.
📌 How to Connect
| Adverb | Meaning | Example |
|---|---|---|
| つい | unintentionally, can't help it | つい食べ過ぎた |
| ついに | at last, finally | ついに完成した |
| (confusable) ついでに | while at it | 買い物のついでに |
💬 Example Sentences
- ダメだと分かっていても、つい甘い物に手が出てしまう。(Even knowing it's bad, I can't help reaching for sweets.) — つい (can't help it)
- 面白くて、つい夜更かししてしまった。(It was so fun I ended up staying up late.) — つい (unintentionally)
- おかしくて、つい笑ってしまった。(It was so funny I couldn't help laughing.) — つい
- 長い闘病の末、彼はついに回復した。(After a long illness, he finally recovered.) — ついに (at last)
- 10年の努力が実り、ついに夢が叶った。(Ten years of effort paid off, and the dream finally came true.) — ついに
🔄 Compare: つい vs ついに vs ついでに vs うっかり
| Expression | Nuance | Example |
|---|---|---|
| つい | “unintentionally, can't help it” (unconscious, often regret) | つい食べ過ぎた |
| ついに | “at last, finally” (a result after a long time) | ついに完成した |
| ついでに | “while at it” (doing along with something) | 買い物のついでに |
| うっかり | “carelessly, by oversight” (a careless slip) | うっかり忘れた |
⚠️ Common Mistakes
- Reversing つい vs ついに: つい = unintentionally; ついに = at last — just に apart, entirely different!
- Confusing with ついでに/うっかり: ついでに = while at it; うっかり = careless slip; つい = involuntary.
- つい often with 〜てしまう: つい〜てしまった (ended up doing, with regret).
- ついに for major results: mostly for long-awaited, major final results (ついに優勝).
💡 Nuance & When to Use
つい means “unintentionally, can't help it, before you know it” (doing something unconsciously or habitually, often with regret: つい食べ過ぎた); ついに means “at last, finally” (a result after a long time and great effort: ついに完成した). Just one 「に」 apart, worlds of difference. つい often with 〜てしまう (with regret); ついに for major, long-awaited results. Don't confuse with 「ついでに (while at it), うっかり (careless)」. A must at N2.
🎯 JLPT Exam Tips
- High-frequency N2: つい (unintentionally, can't help it, unconscious) vs ついに (at last, the result after a long time) — just に apart, entirely different!
- Collocation: つい often with 〜てしまう (with regret); ついに for major results.
- Confusables: つい/ついに/ついでに (while at it)/うっかり (careless).
🖊️ 練習題（5題）
Q1. 「ダメだと分かっていても、___甘い物に手が出る。」（不由得）
(A) つい (B) ついに (C) ついでに (D) ついては
Q2. 「長い闘病の末、___回復した。」（終於）
(A) ついに (B) つい (C) ついでに (D) つまり
Q3. 「つい食べ過ぎた」の意味は?
(A) 不知不覺吃太多了（無意中）
(B) 終於吃到了
(C) 故意吃多
(D) 不想吃
Q4. 「つい」と「ついに」の違いは?
(A) つい＝不知不覺/不由得;ついに＝終於/最終
(B) 兩者完全相同
(C) つい＝終於
(D) ついに＝不知不覺
Q5. 用法が自然なのは?
(A) つい笑ってしまった。 (B) つい完成した(終於の意味で)。
(C) ついに食べ過ぎた(不知不覺の意味で)。 (D) ついに、つい同じ。
答案解析
1. (A) つい ── 不由得伸手拿甜食。
2. (A) ついに ── 終於康復。
3. (A) ── 不知不覺吃太多。
4. (A) ── つい 不知不覺;ついに 終於。
5. (A) ── 「つい笑ってしまった」(不由得)正確。