平白无故

píng bái wú gù zhēng chǎo qi lai

平白无故争吵起来

start arguing for no reason

zhè yī dìng bù huì shì píng bái wú gù de

这一定不会是平白无故的。

There must be some reason for this.

píng bái wú gù ái le yī dùn mà

平白无故挨了一顿骂

get a scolding for no reason at all

tā bù kě néng píng bái wú gù de lí kāi tā

她不可能平白无故地离开他。

It was impossible that she left him for no reason at all.

zuó tiān tā fā le hǎo dà yī tōng pí qi píng bái wú gù de mà le wǒ

昨天他发了好大一通脾气，平白无故地骂了我。

Yesterday, he worked himself into a real frenzy and yelled at me for no reason at all.

tā píng bái wú gù de fā huǒ

他平白无故地发火。

He got angry for no reason.