Native speakers traditionally occupy a special position in foreign language teaching and learning because their language use is norm-providing. In linguistic studies they are crucial as informants because they decide whether an utterance is correct or incorrect. Although Esperanto as a planned language aims at facilitating international communication by means of a common second language, there are also people who speak this language as a mother tongue, a fact that has recently received growing attention both within and beyond the Esperanto-speaking community. The phenomenon deserves attention because it throws light on the character of the speech community, and especially on questions of language loyalty and speaker identity. In addition, the use of Esperanto as a family language stimulates the development of the language. However, the status of Esperanto native speakers cannot be equated with the status of native speakers of an ethnic language both because of their limited number and also because Esperanto is only one of their mother tongues among several. Above all, native Esperanto speakers do not decide on the standard of the planned language.