expend (something) on (someone or something)
To use some resource to attempt to make a change of some kind in someone or something in particular. I don't want to expend much energy on my side business anymore because I'm just not making that much money from it. We don't have to expend much training time on Lisa—she already knows the ropes.
expend something on someone or something
to use something on someone or something. Don't expend too much energy on him. He isn't worth it. There is no point in expending any more money on this car.