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.
(..) My mates. Larry and Barry. If they don't get me, the Night Fevers will. We only got four for big boy here, so he's all but useless. But... ...we can squirt off this little pinky about times. Angharad used to call it Anti-seed. (..)2015 Mad Max: Fury Road