Is Knowing Real? Is Assumption & Skepticism Real?

[PetarKa]

The following questions have been boggling me for a many months:

• What is KNOWING?
• What is TRUTH? (Not "What is the the Truth?", but "What is the nature of Truth? What distinguishes it from Falsehood?")
• What is A QUESTION?
• What is AN ASSUMPTION? What is A PROBABILITY?

I think they are quite interconnected and basically point to the same thing.
Don't know if you still check this section of the forum so I'll tag you... @Leo Gura