未能达到的用英文怎么说

未能达到的用英语可以表示为 "unattainable"。

这个词来源于拉丁文 "attainere"，意思是 "to reach, to arrive at, to achieve"。

例句：

His dream of becoming a famous musician seemed unattainable to him. 他成为著名音乐家的梦想似乎是不可能实现的。
The idea of world peace may seem unattainable, but we can still strive for it. 世界和平的理念可能看起来是不可能实现的，但我们仍然可以为之奋斗。