helpless 是形容词,名词是helplessness.
无奈,根据上下文可有很多不同说法,用have no choice（别无选择）,要比helpless恰当.
In this case,I have no choice.
关於这件事,我很无奈/我别无选择.
Some old people are often condemned to live alone.
一些老人常出於无奈而独自生活.
helpless 是形容词,名词是helplessness.
无奈,根据上下文可有很多不同说法,用have no choice（别无选择）,要比helpless恰当.
In this case,I have no choice.
关於这件事,我很无奈/我别无选择.
Some old people are often condemned to live alone.
一些老人常出於无奈而独自生活.