あっ

A short, sharp exclamation marking a sudden reaction—surprise, alarm, or the moment of noticing or remembering something. The small っ gives it an abrupt, clipped sound.

Typical uses

• Noticing something suddenly: あっ、雨(あめ)だ (Oh, it's raining)
• Warning or alarm: あっ、危(あぶ)ない (Look out!)
• Sudden recollection: あっ、そうだ (Oh, that's right)

Similar words

• ああ: ah — longer; can express understanding, admiration, or dismay
• あれ: huh? — expresses puzzlement that something is unexpected