also: じゃう
auxiliary verb, godan verb (-u)
Expresses completion or thoroughness, often with a sense of finality or regret. Contraction of てしまう/でしまう.
宿題を全部やっちゃった。
I finished all my homework.
ケーキを一人で食べちゃった。
I ate the whole cake by myself.
auxiliary verb, godan verb (-u)
Expresses an unintended or regrettable action. Often used when something happens by mistake or against one's will.
電車に傘を忘れちゃった。
I accidentally left my umbrella on the train.
秘密を言っちゃった。
I blurted out the secret.