How can modern Icelanders still read many Old Icelandic sagas?

Modern Icelanders are able to read Old Icelandic sagas without difficulty primarily because the Icelandic language is the most conservative of the Scandinavian languages. While other languages in the region underwent significant changes, Icelandic preserved its Old Scandinavian grammar, vocabulary, and orthography almost intact since the classical period.1

The language remains highly structured, maintaining three genders, four noun cases, and complex verb and pronoun systems that have changed very little over the centuries. This linguistic stability is attributed to several factors, including Iceland's geographic isolation, a scattered population, and a strong literary tradition that prioritized the use of the native tongue.1

Although pronunciation has evolved significantly since the time of the sagas, the written form remains accessible. Furthermore, a puristic movement beginning in the 19th century helped replace many foreign loanwords with native Icelandic elements, ensuring that the language retained its distinct character and connection to its medieval roots.1