Good question pogo.
It's like this- When the person who's doing the "wanting" is the same person who's actually going to do the action, then you don't use subjunctive.
"Quiero ir al cine"- I want to go to the movies- I'm doing the wanting and I'm the one who would go.
"Quiero que (el) vaya al cine"- I want him to go to the movies- I'm doing the wanting, but I want someone else to do the action.
Note- "vaya" in this sentence and *only* refer to him/her/usted it cannot by "yo" because you only use the subjunctive when the "wanter" and the "wanted" are different people. You could say:
"Quiere que vaya al cine" and that would be He/She wants me to go to the movies.
¿Quiere que lo haga? would be "Do you want/would you like me to do it?"
"El quería que yo hiciera algo" (past subjunctive)- He wanted me to do something- The subject and object are different people.
but
"El quería hacer algo"- He wanted to do something- Subject and object are the same person
Let me know if that makes sense, if not I'll keep on explaining.
