筋疲力尽用英语可以说成 exhausted。这个词来源于拉丁语，原意是“抽干，用尽”。例句：

I'm exhausted after running a marathon. (我跑完马拉松后筋疲力尽了。)

She was exhausted from working all day. (她整天工作后筋疲力尽。)

The soldiers were exhausted after fighting for days. (士兵们连续几天战斗后筋疲力尽了。)