It's 'useless' trying to change her mind. = It's 'useless' to try to change her mind.
Drugs are 'useless' in treating the condition.
I made a 'useless' attempt at fixing the leak.
(..) You understand this is sacred land. These are Judean graves. I'm informing Pilate. If you rule as occupiers, you will be met with disaster, I promise. Are you as treasonous as you are useless? JUDAH: That's my brother's bow. You should be resting. I'm fine. I need to redress the wound. Sit. (..)2016 Ben-Hur