One can work in Ireland if he/she is registered as a full-time student in a course lasting at least one year. Since 2005, not just any course will satisfy the government. But the course must also be listed on a special Register of Programmes. This requirement closes off an avenue used by some people to remain in Ireland by enrolling in a short language course and then working full time.
Only students attending a full time course of at least one year’s duration are entitled to take up part-time employment (defined as up to 20 hours part time work per week or full time work during college vacation periods). This was done just to ensure that a student does not misses his/her studies.