by mistake

Be careful that you don't set the fireworks off by mistake.

当心点, 别弄起那些爆竹爆炸。

He took his neighbour's raincoats by mistake, so he hung them back outside.

他收邻居家的雨衣, 于是又它们挂回原处。

She let the news slip by mistake, in an unguarded moment.

她一不留神泄漏消息。

She sprayed hair spray in her eye by mistake.

她洗头水当成眼药水上到眼睛里。

I locked him in by mistake.

我误他锁在屋里。

He made this mistake by accident.

他犯这个误纯属偶然。