In the humanities and social sciences the Swedish Education System seeks to encourage students to take responsibility for their own learning. This involves emphasis on developing analytical and communicative skills. Often courses are constructed around oral discussions of course topics, and written assignments in which the students are asked to both demonstrate a knowledge of the literature and an ability to evaluate and discuss the literature and compare it to other information. Students should be prepared to do a lot of readings on their own, and to work on how to write reports and papers. This requires good language skills.
In my experience international students are in many cases not familiar with paper writing, and struggle with language requirements. I would recommend international students planning to study in Sweden to find out in advance what the course requirements are in terms of attendance, assignments, and grading practices, and to work on their English skills even if formal requirements are fulfilled.