The paper is devoted to the concept of «zone of proximal development» (ZPD). This fundamental concept is revealed in the framework of the ergative model of the subject of work and learning. The prime postulate of the model is the statement about the genetic unity of the subject of collective activity (the ergasystem) and the individual subject. The similarity of structures was followed by the cultural and historical development of homo sapiens, which occurred in the labour conditions that promoted building human relations. Generalized functions in the ergasystem and the corresponding positions can approximately be as follows: «executor», «leader», «ideologist» and «strategist». The paper states that the subject of educational activity is represented by the same basic characteristics. At any learning stage, the teacher must judge the necessary pedagogical influences according to which subject positions to be improved. Using the ZPD toolkit, the teacher directs efforts to raise the general maturity of the learner, which will develop the ability to learn independently. In order to verify the assumption mentioned above, the method of the teaching experiment was used, during which the students of the secondary vocational education and high school students were attending additional training courses at the Department of Further Education, The Small Academy, Lomonosov Moscow State University. Extra training courses included project or research activities of trainees, so groups of students acted both the subject of collective work and the subject of learning. The first results of the pilot experiment showed that productive work of the teacher and student can be carried out at the intersection of the subject spaces of these activities, where the boundaries of the ZPD can be outlined.