我迟到是因为交通的缘故。
wǒ chídào shì yīnwèi jiāotōng de yuángù 。
I was late because of the traffic reason.
请告诉我这个决定的缘故。
qǐng gàosù wǒ zhègè juédìng de yuángù 。
Please tell me the reason for this decision.
他没有来是有缘故的。
tā méiyǒu lái shìyǒu yuángù de 。
There is a reason why he didn't come.