Here you can read a description for the different types of actions you can take:
In general you have the following actions per round:
- 1 standard action
- 1 move action
- 1 swift action
- any logical amount of free actions
You can exchange your standard action for an extra move action, or exchange both your standard and move action for a full round action, but you can never exchange a move action for a standard or a swift action.
Full round actions are specific actions like a full attack (make all your iterative melee or ranged attacks, not spells), charge, withdraw, etc., not a double standard.
So if you can't cast a spell as a swift action (i.e. via quick cast) then you can't cast more than one spell per round.