“〜ni kizuku・〜ki ga suru・〜ki ni naru”: Notice / Feel / Be Concerned [JLPT N4]
Content by NTJ Kuma · Nihongo to Japan editorial team · Updated July 27, 2026
「間違いに気づく」「忘れた気がする」「彼が気になる」 — noticing, sensing, and being preoccupied.
Three 「気」 words — 気づく, 気がする, 気になる, all different
「間違いに気づいた」 (I noticed the mistake), 「なんか変な気がする」 (something feels off), 「彼女のことが気になる」 (I keep thinking about her) — all three contain 「気」 yet mean completely different things: 〜に気づく = notice (realize a fact); 〜気がする = (subjectively) feel, have a hunch; 〜が気になる = be bothered by, mind, be curious about. This guide sorts these often-confused 「気」 expressions with three situations.
The three 「気」 expressions
- 〜に気づく = notice, realize (suddenly noticing a fact you'd overlooked): 忘れ物に気づいた (noticed I forgot something).
- 〜気がする = (subjectively) feel, have a hunch (a groundless intuition): どこかで会った気がする (I feel we've met somewhere).
- 〜が気になる = mind, be preoccupied, be curious (can't let go, want to know): 試験の結果が気になる (I'm anxious about the exam results).
How to Connect
| Form | Meaning | Example |
|---|---|---|
| noun ＋ に気づく | notice, realize | 間違いに気づく |
| plain form ＋ 気がする | (subjectively) feel | 変な気がする （something feels off） |
| noun ＋ が気になる | mind, be curious | 結果が気になる （the result is on my mind） |
Examples in use
- 提出する前に、答えの間違いに気づいた。(I noticed the wrong answer before submitting.) — notice
- テストの答えが間違っている気がする。(I feel the test answer is wrong.) — subjective feeling
- となりの席の人が気になって、集中できない。(The person next to me is distracting; I can't focus.) — bothered
- 財布を忘れたことに気づいて、家に戻った。(I realized I'd forgotten my wallet and went home.) — notice (ことに)
- 彼女のことが気になる。(I keep thinking about her／I'm interested in her.) — preoccupied／curious
⚠️ Common mistakes to avoid
① The three differ — don't mix them. 気づく = notice a fact (objective realization), 気がする = subjective hunch (feel unsurely), 気になる = mind (can't let go, curious). English may say “feel／mind” for all, but Japanese keeps them distinct.
② Different particles. 〜に気づく (気づく takes に), 〜が気になる (気になる takes が). Wrong particle sounds off.
③ 「気になる」 carries curiosity／ambiguity. 「彼のことが気になる」 = I'm preoccupied with him (can't let go), often implying “I have feelings for him.” Used of people, the nuance is delicate — use with care.
🔄 Compare: 気づく／気がする／気になる／気に入る
| Form | Meaning | Example |
|---|---|---|
| 〜に気づく | notice, realize (a fact) | 間違いに気づく |
| 〜気がする | subjective feeling, hunch | 会った気がする （I feel like I've met them before） |
| 〜が気になる | mind, preoccupied, curious | 結果が気になる （the result is on my mind） |
| 〜が気に入る | take a liking to | この服が気に入る （I like this outfit） |
💡 Learning tip
These three 「気」 words easily blur under English “feel／mind”; three images keep them apart: 気づく = “ah, I've noticed!” (realize a fact); 気がする = “I kind of feel…” (an unsure hunch); 気になる = “it's really on my mind” (preoccupation, curiosity). Memorize the particles too: に気づく, が気になる. Note that 「彼が気になる」 often carries an “I have feelings for him” nuance, so use it of people with care. Distinguish these three and your Japanese gets far more nuanced.
❓ Questions you might have
Q: 「気がする」 vs 「気づく」?
Completely different! 「気がする」 = a subjective, unsure hunch (会った気がする = I feel we've met, but not sure); 「気づく」 = objectively noticing a fact (間違いに気づく = noticed the mistake, definitely registered it). One is “a vague feeling,” the other “a clear realization.”
Q: Are 「気になる」 and 「気に入る」 the same?
No! 「気になる」 = mind, be preoccupied, curious (結果が気になる = anxious about the result, can't let go); 「気に入る」 = take a liking to, be pleased with (この服が気に入る = I like this outfit). One is “can't stop thinking about,” the other “came to like” — one word apart, very different.
🖊️ Practice Quiz
Q1. 「財布を忘れた___。でも本当かどうかわからない。」(I feel like I forgot my wallet, but I'm not sure)
(A) に気づいた (B) 気がする (C) 気になる (D) に気がした
Q2. 「テストの答えが間違っていた___。」(noticed the test answer was wrong — an objective fact)
(A) 気がする (B) 気になる (C) に気づいた (D) を気づいた
Q3. 「となりの席の人が___。」(the person next to me is on my mind / I'm drawn to them)
(A) 気がする (B) に気づいた (C) 気になる (D) 気をつける
Q4. What is the core nuance of 「気がする」?
(A) objectively noticing a fact
(B) the speaker's subjective intuition/vague feeling
(C) worrying about / minding something
(D) being careful
Q5. 「彼女のことが___。」(I'm a bit interested in her / maybe like her)
(A) 気がする (B) 気になる (C) に気づいた (D) 気分だ
Answer Key
1. (B) 気がする ── 忘れた気がする = I feel like I forgot it (subjective intuition); the ‘not sure' confirms it's a vague feeling.
2. (C) に気づいた ── 間違いに気づいた = noticed the mistake (objective realization).
3. (C) 気になる ── 気になる = be on one's mind / drawn to.
4. (B) ── 気がする = the speaker's subjective intuition/vague feeling.
5. (B) 気になる ── 彼女のことが気になる = I'm interested in / drawn to her.