枉然的英文：
in vain

参考例句：

It is no use crying over spilled milk.
[谚]牛奶翻倒，哭也枉然。(覆水难收。)

Birth is nothing where virtue is not. ——Moliere
品德不好，出身高贵也枉然。——莫里哀

It seems that all our efforts are futile and we have to submit to the will of Heaven.
看来,一切努力都是枉然,只有听天由命了。

a horse is a false hope; his great power will not make any man free from danger.
靠马得救是枉然的。马也不能因力大救人。

He's dead and it's no use wishing him alive again.
他已经死了,希望他再活过来的想法也是枉然.

therefore, to exhort her to repentance and to confession, as a proof and consequence thereof.
因此，应该由你来规劝她悔过和招供，以证明你尽职尽责并非枉然。”

To bless thee, yet renounce thee to thy face.
哪怕是怎样枉然，也要爱你到底;;也要祝福你－－即使拒绝你在当面。

vain是什么意思：
adj. 空虚的；无价值的；徒劳的；无效的；自负的；爱虚荣的

It was a vain effort.
这种努力是徒劳无益的。

This is a vain and fleeting thing.
这是一种空虚的、转瞬即逝的东西。

She is vain and extravagant.
她既爱虚荣又奢侈。

I pleaded for him in vain.
我为他辩护未成。

It is in vain, sir, to extenuate the matter.
先生，大事化小，小事化无的做法无济于事。