出于什么原因用英语怎么说

"出于什么原因" 用英语可以说作 "for what reason" 或 "for which reason"。

这个短语是由 "for" 和 "reason" 两个单词组合而成，"for" 意思是 "因为"，"reason" 意思是 "原因"。

例如：

Can you tell me for what reason you're leaving?
(你能告诉我你离开的原因吗？)
For which reason did you decide to stay?
(你为什么决定留下？)