他们无意中听到她唱歌。用英语怎么说？

他们无意中听到她唱歌。

They overheard her singing.

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

overheard

v. 偶然听到(overhear的过去式和过去分词)；

例句
He was having to whisper in order to avoid being overheard by their nosy neighbours...
他不得不小声说，免得被爱管闲事的邻居们听到。

her

pron. (she的宾格)她，(she的所有格)她的，她，指某个国家，（一艘）船；

例句
There was a terrible sadness in her eyes...
她眼神中流露出深深的悲伤。

singing

n. 唱歌，鸟鸣，<物，无>振鸣，（机器或系统）技术先进；v. 唱，歌唱(sing的现在分词)，（鸟）鸣，嗡嗡叫，呜呜作响；adj. 唱歌的，音乐般的；

例句
She loved singing as a child and started vocal training at 12.
她从小就喜欢唱歌，12岁开始了声乐训练。