副詞 in vain:

1. to no avail
   同義詞：vainly

1. Day after day she waited in vain for him to telephone her.
   日復一日，她徒勞地等待他的電話。
2. They endeavoured to make her happy but in vain.
   他們盡量使她快樂，卻徒勞無功。
3. All our work was in vain.
   我們的工作全都白干了。
4. I sought to persuade him, but in vain.
   我試圖說服他，但無效。
5. He tried in vain to catch the butterfly on the flower.
   他白費力氣想抓住停在花上的蝴蝶。
6. All his father's exhortations were in vain.
   他父親的一切勸告都無效。
7. We tried in vain to make him change his mind.
   我們想使他改變主意，結果是白費心機。