Spoken chiefly in Iceland, where it is the official language, it stems from Old Norse, the language of the Vikings who settled the island in the 9th cent. Before that date the language is considered Old Icelandic, which is classified as belonging to the western branch of Old Norse. Unlike the other Scandinavian languages, Icelandic is noted for its conservatism in grammar, vocabulary, and spelling.
Verbs have a highly developed inflectional system.
In matters of vocabulary, there has been a strong purist movement for several centuries. For example, instead of directly adopting modern scientific terms, Icelandic renders them by translations or by newly created compounds and expressions formed from native words. Actually, Modern Icelandic has changed so little from its parent language, Old Norse, in the course of the centuries that Icelanders today read the Eddas and sagas of Old Norse literature more easily than the English and the Americans read Shakespeare. One reason for the relative stability and purity of Icelandic is that its speakers lived for centuries in comparative isolation on an island and thus were not much influenced by other languages. The Roman alphabet came to Iceland c.1000, along with Christianity.