他已老而无用了。用英语怎么说？

他已老而无用了。

He has outlived his usefulness.

he

pron. 他，它，一个人；n. 雄性动物；

例句
Logic had prevailed and he had abandoned the idea.
最终理智占了上风，他打消了那个念头。

has

v. 有( have的第三人称单数 )，（亲属关系中）接受，拿，买到；

例句
...the operation a patient has had.
病人做过的手术

his

pron. (he的所有格)他的，(he的物主代词)他的东西；det. 属于他的，用于名词前，自己的，指某人的，上帝的；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

usefulness

n. 有用，有益，有效，效能；

例句
The attitude of the parents toward the usefulness of what is learned must colour the way children approach school.
父母对学知识是否有用的态度必定会影响孩子对待学业的态度。