The diploma thesis focuses on teaching grammar in the context of in-company language courses. What needs to be taken into consideration are both the psychological aspects of adult learners and the sociological characteristics of a typical course participant, their position of a client which is connected to high expectations of the service provided - language tuition. The role of the teacher in an in-company course is much less authoritative than in a traditional course and teachers become rather partners or coaches for the learners. The pedagogical research conducted among 172 Czech in-company learners with the help of an electronic questionnaire shows that the main aim of in-company students is to be able to communicate efficiently in real-life situations from their private and working lives. It is the role of the teacher, or the coursebook author, to choose which grammar structures are necessary to succeed in the respective situations. Therefore, the most suitable method for teaching grammar in the context of in-company courses is the Engage, Study, Activate method combined with the eclectic method.