Devlin, Thomas Moore (2019年4月25日). “What Is Esperanto, And Who Speaks It?” (英語). Babbel Magazine. 2022年5月14日閲覧。 “Evidence also shows that he learned Yiddish from his mother and that he studied German, English, Spanish, Lithuanian, Italian and French. In addition, Zamenhof learned the classical languages Hebrew, Latin and Aramaic in school. Esperanto was not even the first constructed language he’d dealt with. First, he learned a bit of Volapük, which was invented in Germany almost a decade before Esperanto. Having command of so many languages had a tremendous impact on his creation of Esperanto, which would be Zamenhof’s 14th language.”
