national language of Iceland, spoken by the entire population, some 300,000 at the turn of the 21st century. It belongs (with Norwegian (Norwegian language) and Faroese (Faroese language)) to the West Scandinavian group of North Germanic languages and developed from the Norse speech brought by settlers from western Norway in the 9th and 10th centuries. Old Icelandic, usually called Old Norse (Old Norse language), is the language in which the s (Edda), sagas (saga), and skaldic poems (skaldic poetry) were written in the Middle Ages. By the time these works were written, several dialectal characteristics that differentiate Icelandic from Norwegian had emerged.

Important factors in the survival of Icelandic during the centuries of Danish rule were its continued use for literary purposes, the geographic remoteness of Iceland, a scattered population, and the great linguistic differences between Danish and Icelandic. While the Scandinavian languages in continental Europe were losing inflection, Icelandic preserved Old Scandinavian grammar almost intact. The native Bible became a basis for the further development of Icelandic. Nevertheless, the circumstances of the language were highly restricted until self-government developed in the 19th century and Icelandic was rediscovered by Scandinavian scholars. A firm orthography along etymological lines was gradually established, and Icelandic today appears strikingly different from the other Scandinavian languages.

In grammar, vocabulary, and orthography, modern Icelandic is the most conservative of the Scandinavian languages. It still has three genders (masculine, feminine, and neuter), four cases for nouns (nominative, genitive, dative, accusative), several declensions, and complicated pronoun and verb systems that have changed little since the classical period. For this reason, Icelanders today can still read the Old Icelandic sagas without difficulty. A great deal of change has taken place, however, in the pronunciation since Old Norse times.

Although Icelandic borrowed words from Celtic, Danish, Latin, and Romance languages, most of these words have been replaced with Icelandic forms since the beginning of the 19th century, when a puristic movement developed; now, all technical and abstract terms are formed from strictly Icelandic elements.