気がつい

In a sentence

• 私が電車に乗っているときに彼女からのメッセージに気がついた。

  I noticed the message from her while riding the train.

  In this sentence, 気がついた (kigatsuita) is used to describe the act of noticing or becoming aware of something, in this case, the message. It conveys a realization or conscious awareness.

• 靴下が破れていることに気がついたのは、家を出た後だった。

  I realized my socks had a hole in them only after leaving the house.

  Here, 気がついた (kigatsuita) indicates the realization or discovery of an issue with the socks after the person had already left home. It emphasizes a retrospective awareness.

• 彼の古い友達が結婚をしたことに気がつかなかった。

  I didn't notice that his old friend had gotten married.

  In this example, 気がつかなかった (kigatsukanakatta) is used to express the lack of noticing or awareness, showing that the speaker failed to realize or perceive the event of the friend's marriage.