A:  You cannot drive in N. Ireland/UK on a provisional licence/learner's permit unless you comply with the following:A client who has a provisional licence for a car or other vehicle (except a motorbike) is subject to the following restrictions:-
• display 'L' plates on the front and back of the vehicle
• must not drive on a motorway
• if the vehicle has more than one seat, s/he must have someone over the age of 21 to supervise her/him whenever s/he is driving. That person must sit in the front passenger seat, have had a full driving licence for at least three years and s/he must be fit to drive the vehicle.

In addition from 30 June 08 you cannot drive on your learner's permit in the Republic unless you are accompanied by someone with a full driving licence.