Terms to know -
Ability - this is the stuff you "purchase" moves with. It goes down when you use it
Skill - this is the level of your skill, it can never go down, but you need a certain "skill level" to be able to learn a move
Round - this is the term given to the ammount of time it takes for EVERYONE in battle to take there turn
Speed - this is what allows you to take many attacks all in one turn, each action you do (in or out of turn) takes speed. Block takes speed, basic attacks take speed, everything. You have only 50 speed. (unless raised by item) And if you run out you CANNOT act. But it replenishes after every round.
Here it goes -