Recent decades have brought significant expansion of the so-called shadow education sector of private supplementary tutoring across the globe. Increasing numbers of school teachers provide such tutoring on a part-time basis; and increasing numbers of tutorial centres recruit teachers from schools to work full time. Tutorial centres also recruit personnel from other backgrounds, who take on roles that could be called tutoring but could also be called teaching. These trends have blurred professional boundaries. They require some reconsideration of vocabularies and of overlapping roles.