You will be made aware of new questions several weeks before the deadline ( 1st April or 1st October). You can then learn the new questions if you know that you will be taking your theory test after the deadline. You will automatically receive the new set of questions after they are valid. 

You can check whether you are learning with the correct question version by clicking on the gear symbol in the main menu. The question version is then displayed in the last line of the account information.