Artificial language created in 1887 by Lazarus Ludwig Zamenhof (1859–1917), a Polish oculist, for use as an international second language.
Zamenhof's Fundamento de Esperanto (1905) outlines its basic principles. All words, derived from roots commonly found in the European languages, are spelled as pronounced, and grammar is simple and regular. Nouns have no gender and end in -o , and there is only one definite article, la (e.g., la amiko , "the friend"). Adjectives are marked by the ending -a . Verbs are regular and have only one form for each tense or mood. The Universal Esperanto Association (founded 1908) has members in 83 countries. Estimates of the number of Esperanto-speakers range from 100,000 to several million.