Is X1 visa strictly a single entry one? Resident permit holder can have multiple entries ?

Hi, Ill be applying soon for X1 type for one year language course. Is X1 allow only single entry ?
If so, How will i be able to go my home country and come back in semester breaks or any emergency arises back at home ?

Is the resident permit solution for this ? Does a resident permit holder ( which i obviously be applying ) have privilege of multiple entries irrespective of number of entries mentioned in X1?