in vain
枉费心机；徒劳无益；白费力气；无用的;无意义的;无价值的
They tried in vain to persuade her to go.
他们极力劝说她去，但枉费了一番口舌。
All our efforts were in vain.
我们的所有努力都付诸东流了。
He stopped at the door, waiting in vain for her to acknowledge his presence...
他在门口停住，徒然地等待她和自己打招呼。
He wants the world to know his son did not die in vain.
他想让全世界都知道，他的儿子不是白白死去的。
Their blood was not shed in vain.
他们的血没有白流。
It became obvious that all her complaints were in vain.
很明显她所有的抱怨都是白费口舌。
She tried in vain to point out to him the unfairness of his actions.
她试图向他指出他的做法不公正，但无济于事。
Throughout the Twenties, Lardner tried in vain to write a hit song, so at last he turned to parody.
整个20年代，拉德纳尝试着想要写出一首走红歌曲，可是都失败了，于是最后转向戏仿他人的作品。
He tried in vain to keep the two dogs apart before the neighbour intervened.
邻居过来帮忙前，他费了半天劲儿也没把两只狗分开。
She and a neighbour tried in vain to revive him.
她和邻居想尽一切办法都没能让他苏醒过来。
She searched in vain for her passport.
她翻找自己的护照，但没找着。
A seemingly endless line of trucks waits in vain to load up.
一眼望不到头的一长列卡车眼巴巴地等着装货。
Parents campaigned in vain for her reinstatement.
父母们呼吁给她复职，但结果却只是徒劳。
My endeavours to bring about a settlement ended in vain.
我试图达成和解的努力全部落空了。
Our efforts were not in vain.; We didn't waste our energy.
我们的力气没有白费。
Our efforts were not in vain.
我们没有白忙。
All efforts of mediation by a third party were in vain at all.
第三方所作的从中调解的一切努力均告失败。
My efforts were not in vain.
我的气力没有白费。
All our efforts were in vain.
我们的所有努力都付诸东流了。
注意：有的状语是说明句子某个成分（例如谓语）的，有的状语则是说明整个句子。运用或翻译时要注意整体修饰作用。请看：
The chief tried to open the locked door but in vain.
小偷试图打开锁着的门，但是一切是徒劳的。（四级真题）
I read his article again and again, trying hard to understand what he was driving at but in vain.
我把他的文章读了一遍又一遍，但对他的意图仍百思不解。
As an inexperienced teacher, I tried every means to get them to be quiet, but in vain.
作为一个没有经验的老师,我想尽一切办法让他们安静下来,但徒劳无功。
高考真题- 2015 湖南
In vain they rush frantically round from place to place, trying to escape from avenging boredom by mere clatter and motion.（新概念4，l58）
他们发狂地东奔西跑，想通过谈笑和活动来摆脱报复般的厌烦，但是这是徒劳的。