Fundamento de Esperanto

Fundamento de Esperanto (English: Foundation of Esperanto) is a book by L. L. Zamenhof, published in the spring of 1905. On August 9, 1905 it was made the official source for the language by the fourth article of the Declaration of Boulogne at the first World Congress of Esperanto in Boulogne-sur-Mer, France:

It is considered the only obligatory authority over Esperanto and is thus unchangeable.

The Fundamento consists of four parts: a Foreword (Antaŭparolo), a Grammar (Gramatiko), a collection of exercises (Ekzercaro) and a "Universal Dictionary" (Universala Vortaro). With the exception of the Foreword, almost everything in the Fundamento comes directly from Zamenhof's earlier works.

Equal to the Fundamento are the "Official Additions" (Oficialaj Aldonoj). To date, there have been nine Official Additions. The Foreword of the Fundamento states:

Nur iam poste, kiam la granda parto de la novaj vortoj estos jam tute matura, ia aŭtoritata institucio enkondukos ilin en la vortaron oficialan, kiel 'Aldonon al la Fundamento'.

Some time from now, when many of the new words have completely stabilized, some authoritative institution shall put them into an official dictionary, as 'Additions to the Fundamento'.

The grammar and dictionary sections of the Fundamento are in five national languages: French, English, German, Russian, and Polish.

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