SUMMARY
In the article the question of the account of tasks complexity at the mastering control of linguistic expressions is considered. It is shown, that complexity of realization of tasks structurally consists of three components: organizational complexity, structural complexity and substantial complexity. Influence of structural and substantial complexity on estimation results of educational students’ activity on formation of answers is experimentally confirmed. The reduced materials allow differentiating efforts of students during mastering linguistic expressions at a reproduction level. Materials of the article can be used for research of expediency of the account of complexity of tasks for other types of tests.