因由

wèn qīng chu yīn yóu

问清楚因由

find out the origin

tā bù chī fàn xiǎng bì shì yǒu yīn yóu de

他不吃饭，想必是有因由的。

He ate nothing; there must be some reasons.

tā néng gòu tòu guò jié guǒ fā xiàn yīn yóu

他能够透过结果发现因由。

He was able to get the cause behind the effect.

shì shàng suǒ yǒu de shì qing dōu yǒu yīn yóu

世上所有的事情都有因由。

There's a reason for everything.