[Grammar pattern] V(て) + ちゃう (regret): Meaning and Example Sentences

A grammar pattern used to express that an action has been completed unintentionally or that something unfortunate or regrettable has occurred as a result of another action.
It is a short form of the pattern "V(て) + てしまう" and is often used in casual conversations with the past form "ちゃった" to express the speaker's feelings of surprise, disappointment, or regret.

あ、いけない。家(いえ)に教(きょう)科(か)書(しょ)を忘(わす)れちゃった。

Oh no, I forgot my textbook at home.
どうして遅(おく)れたの？ーごめん。違(ちが)う電(でん)車(しゃ)に乗(の)っちゃったんだ。

Why were you late? - Sorry, I got on the wrong train.
どうしたの？ー宿(しゅく)題(だい)を忘(わす)れて、先(せん)生(せい)に怒(おこ)られちゃった。

What happened? – I forgot my homework and got scolded by the teacher.
手(て)帳(ちょう)を汚(よご)しちゃったから、新(あたら)しいのを買(か)った。

I stained my planner, so I bought a new one.
部(ぶ)長(ちょう)、会(かい)社(しゃ)をやめるそうだよ。社(しゃ)長(ちょう)と話(はな)しているのを聞(き)いちゃった。

I overheard the department manager saying he’s quitting the company. He was talking to the president.