by mistake

She sprayed hair spray in her eye by mistake.

她把洗头水当成眼药水上到眼睛里了。

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

她一不留神泄漏了消息。

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

当心点, 别弄了引起那些。

I locked him in by mistake.

我误把他锁屋里了。

He made this mistake by accident.

他犯误纯属偶然。

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

他收了邻居家的雨衣, 于是又把它们挂回原处。