Icelandic is the official language of Iceland and preserves four grammatical cases: nominative, accusative, dative, and genitive.
Icelandic is a North Germanic language descended from the language brought to Iceland by Norse settlers during the settlement period. Its written tradition includes the medieval Icelandic sagas, which provide some of the most important literary sources for Old Norse culture.
Modern Icelandic has changed over time, but its inflectional system retains features that have disappeared or become less prominent in several closely related Scandinavian languages. Nouns, adjectives, and pronouns can change form according to case, number, and grammatical gender.
Icelandic speakers can often recognize older forms in medieval texts more readily than speakers of some other modern Germanic languages can recognize comparable early literature. That does not make Icelandic unchanged: pronunciation and vocabulary have developed, and modern terminology continues to be created.