In general, written Swedish differs considerably from both Danish and Norwegian, but written Danish and Norwegian are pretty similar, although there are two official written forms of Norwegian: Bokmål and Nynorsk. Swedish is the only Scandinavian language to use ä and ö, whereas Danish and Norwegian use æ and ø. Swedish is also the only Scandinavian language to use x in words such like extra, which would be spelt with ks in Danish and Norwegian - ekstra. There are also a range of differences in vowels, for example the words for milk: Danish mælk, Norwegian melk/mjølk and Swedish mjölk is one example, and the words for eye, Danish øje, Swedish öga and Norwegian øye is another.