While many people think it must be common sense for Swedish to be the official language of Sweden, it wasn’t until 2009! Swedish is a North Germanic language that is extremely similar to other Scandinavian languages such as Danish and Norwegian.
Because of the prevalence of other languages, Swedish was not made official until 2009. While today most everyone speaks Swedish as at least a second language, almost as many people speak English. Almost everyone in Sweden speaks English because of the trade links established after World War II and a strong Anglo-American influence that was established.
English became a mandated course taught in schools because it was so prevalent in the country. Because it is so popular, many people called for the strengthening of Swedish, thus it was officially made the language of Sweden!