気

気 is a versatile noun meaning spirit, mood, or attitude. In everyday usage, it often expresses a sensation or impression (気がする: to have a feeling that something is the case), concern or interest about something (気になる: to be curious or worried about), and personal precautions or mindset (気をつける: to be careful; to watch out). It also forms common words like 気持ち (feeling) and 気分 (mense/feeling at the moment). Use 気 in contexts where you describe internal states, impressions, or the approach you take toward actions and situations.