The Sweden Embassy in Pakistan recommends ( although not mandatory ) that you have taken a Swedish Language course somewhere or you can understand atleast the basics of Swedish Language. " If you want to experience the real life of the city, you must learn the language. If you don't know many people, enroll at a language school."
Some Sweden Universities and Colleges also conduct ( free or charged ) Swedish language course before the start of the studies. Your university or college would inform you of any such opportunity. If it is free, then it is strongly recommended to attend such a course.