Esperanto

L. L. Zamenhof, a Polish ophthalmologist, introduced Esperanto in 1887 with the publication of the first textbook, Unua Libro. He proposed it as an international second language intended to help people communicate across linguistic and cultural divisions. The name Esperanto derives from the pseudonym under which the first book appeared.

Esperanto uses a regular system of word endings and largely phonetic spelling. Its foundational grammar specifies, among other features, a single definite article, la; noun endings in -o and adjective endings in -a; and verb endings that distinguish tense and mood without changing for person or number. The Fundamento de Esperanto, published in 1905, established a reference for the language's core rules and vocabulary.

Esperanto developed beyond its original proposal into a language used in writing, conversation, translation and organized international gatherings. Its history illustrates both the appeal and limitations of planned languages: a carefully designed system can attract a community, but that does not by itself make it the world's dominant means of international communication. A scholarly review published in 1999 noted that Esperanto had not become a dominant worldwide language, despite its logical design and continuing interest.