Here, i'll rephrase my explaination with the yes or no question instead
You would ask this:
*point to a door* (and lets just say its the door that leads to death) "If I asked the other guard if this was the door that leads to freedom, what would he say?"
So, if by chance you happen to ask the liar, this is what happens. The liar KNOWS that the other guard (being the truthful one) will say no, but since the liar knows this, he will lie and say yes to you.
If by chance you happen to ask the truthful guard, this is what happens. The truthful guard KNOWS that the liar would say yes (because he knows he would lie) so the truthful guard has to say yes because he is honest and just answering the question you asked.
With all this in mind, whether you ask the truthful guard or the honest guard, they will both have the same answer. Therefore, if the answer is yes, the door you pointed out is NOT the door to freedom. If the answer is no, the door you pointed out IS the door to freedom.
Understand, kids?