the fact of being of no use, or of not working or achieving what is needed

They complained bitterly about the uselessness of their training. 他们强烈抱怨训练毫无用处。

She knew the complete uselessness of arguing with him any longer. 她知道再跟他争吵是完全没有用的。

the quality of not being at all good at doing something

He is known as Mr Wrong for the uselessness of his predictions. 他被称为错误先生，因为他的预测毫无用处。

She tells bad jokes about the uselessness of men. 她爱讲关于男人无用的粗俗笑话。