Importance. Teaching foreign students of engineering and technical profile to complex specific text-forming structures of scientific style of speech is a laborious process. The identification of the causes and mechanisms of the occurrence of the errors noted in the structure of a complex sentence, their analysis (identification, elimination, correction) facilitates the process of studying these important grammatical units. The purpose of the research is to develop a new approach (erratological) to the study of a complex sentence based on error analysis. Its structural and meaningful description is proposed. Materials and methods . The study is conducted on the basis of the Military Institute (Engineering and Technical) Military Academy of Logistics named after Army General A.V. Khrulev. The research material is a corpus of “negative material” obtained as a result of an experimental study of the speech of engineering students. The corpus of violations in a complex sentence formed the basis of the approach we developed, called the “erratological approach”. This study is also based on the analysis and generalization of scientific works on erratology. Results and Discussion . An erratological approach to the study of complex structures of the scientific style of speech has been developed, including six main interrelated stages – the selection of grammatical material, the organization of grammatical material (its logical arrangement), the introduction of grammatical material (presentation in classes in the language of the specialty), training, practice, control, which allow you to form not only Russian-speaking professional competencies, but also skills for all types of speech activity. Conclusion . The use of an erratological approach, namely complex work with one’s own mistakes in the classroom, will ensure the student’s undoubted interest in learning a new language, will contribute to the intensification of the educational process, enrich it with new technologies, teaching methods, a new system of tasks, will form both linguistic and professional competence.