Native Esperanto speakers (Esperanto: denaskuloj or denaskaj esperantistoj) are people who have acquired Esperanto as one of their native languages. As of 1996, there were 350 or so attested cases of families with native Esperanto speakers. Estimates from associations indicate that there are currently around 1,000 Esperanto-speaking families, involving perhaps 2,000 children. In all known cases, speakers are natively bilingual, or multilingual, raised in both Esperanto and either the local national language or the native language of their parents. In all but a handful of cases, it was the father who used Esperanto with the child. In the majority of such families, the parents had the same native language, though in many the parents had different native languages, and only Esperanto in common.
Raising children in Esperanto occurred early in the history of the language, notably with the five children of Montagu Butler (1884–1970). Because of this, some families have passed Esperanto on to their children for several generations. A famous native speaker of Esperanto is businessman George Soros, son of Tivadar Soros, publisher and writer in Esperanto. Also notable are young Holocaust victim Petr Ginz, whose drawing of the planet Earth as viewed from the moon was carried aboard the Space Shuttle Columbia, and Daniel Bovet, the recipient of the 1957 Nobel Prize in Physiology or Medicine.
Esperanto is not the primary language of any geographic region, outside of temporary gatherings (such as conventions like the World Congress of Esperanto) and isolated offices (such as the World Esperanto Association's central office in Rotterdam). Consequently, native speakers have limited opportunity to meet one another except where meetings are specially arranged. For this reason, many parents consider it important to bring their children regularly to Esperanto conventions such as the annual "Renkontiĝo de Esperanto-familioj" (or "Esperantistaj familioj"; REF, since 1979). Similarly, the annual Children's Congress of Esperanto happens alongside the largest Esperanto convention, the World Congress of Esperanto (Universala Kongreso)....LESS