His efforts were unsuccessful.

他的努力失败了。

...a second unsuccessful operation on his knee.

他第二次失败的膝盖手术

There were reports last month of unsuccessful negotiations between guerrillas and commanders.

有报道称上月游击队和指挥官之间的谈判失败。

The difference between successful and unsuccessful people is that successful people put into practice the things they learn.

成功者与失败者的区别在于成功者能够学以致用。

He and his friend Boris were unsuccessful in getting a job. [+ in]

他和他朋友鲍里斯都没有找到工作。