気(き)がつく

きがつく
expression
to notice; to realize; to become aware
cognition
1. to notice; to realize; to become aware of
To perceive or become conscious of something that was not previously noticed.
間違(まちが)いに気(き)がついた。
I noticed the mistake.
彼(かれ)がいないことに、誰(だれ)も気(き)がつかなかった。
Nobody noticed that he was gone.
駅(えき)に着(つ)いてから、財布(さいふ)を忘(わす)れたことに気(き)がついて慌(あわ)てた。
After arriving at the station, I realized I had forgotten my wallet and panicked.
2. to be attentive; to be considerate; to be thoughtful
To be naturally observant of others' needs and feelings.
彼女(かのじょ)はよく気(き)がつく人(ひと)だ。
She is a very attentive person.
気(き)がつく子(こ)だね、ありがとう。
What a thoughtful child — thank you.
周(まわ)りの人(ひと)の変化(へんか)にすぐ気(き)がつくのは、彼女(かのじょ)のいいところだ。
One of her good traits is that she quickly notices changes in the people around her.

A very common expression composed of 気(き) (awareness, attention) + が + つく (to attach, to arrive at). Describes the moment of becoming aware of something, or a person's quality of being naturally attentive. Also written as 気(き)が付(つ)く.

Usage

  • Sense 1 pattern: ～に気(き)がつく (to notice ~)
  • Sense 2 is used as a personality trait: 気(き)がつく人(ひと) (a considerate person)
  • The contracted form 気付(きづ)く is more common in writing
  • Past form 気(き)がついた is very frequently used

Common collocations

Similar words

  • 気付(きづ)く: to notice, realize — contracted form; same meaning, more common in written Japanese
  • 気(き)にする: to worry about, care about — different nuance; focuses on concern rather than noticing
  • 気(き)になる: to be on one's mind — something catches attention and lingers
  • 感(かん)づく: to sense, have a hunch — implies intuiting rather than clearly noticing

Related Words

Compare: 気付(きづ)く (to notice, realize)
Compare: 気(き)にする (to worry about, care about)
Compare: 気(き)になる (to be on one's mind)
Compare: いつの間(ま)にか (before one knows it, unnoticed)
Compare: 思(おも)い付(つ)く (to think of, to hit upon)
Compare: 我(われ)に返(かえ)る (to come to one's senses)
general
Added 2026.4.4 2:13 · Revised 2026.9.4 21:31
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