1、His efforts to fix the problem were ineffectual.
他试图解决问题，但无效。

2、The organization's response to the crisis was ineffectual and lacked direction.
该组织对危机的反应无效且缺乏方向。

3、Despite their best intentions, their attempts to help were ultimately ineffectual.
尽管他们怀着最好的意图，但他们的帮助尝试最终无效。