Native Esperanto speakers come to be in families in which Esperanto (and usually other languages) are spoken. Often one or both parents choose to use Esperanto as the main language in communicating with the children, who thus acquire the language in the way as other children acquire their native languages. Usually those children become natively bilingual, trilingual, or even more. It also happens that the parents use Esperanto between themselves, but use another language in speaking with the children. Then the children, who wish to understand what the parents are saying between themselves, learn to at least comprehend spoken Esperanto.
It is generally imagined that this occurs most often in families in which the parents speak different languages, and meet and fall in love at Esperanto congresses. While there are many of those families, most often both parents have the same native language. In that case one of the parents, usually the father, chooses to use Esperanto with the children in order to enrich their native knowledge and experience.
As with all children who speak a language that is not the mainstream one in their culture, it is extremely helpful to meet regularly with other native speakers. It is therefore important to the language skill of native Esperanto speakers if parents regularly bring their children to Esperanto conventions. The annual Children's Congress of Esperanto[?] (Infana Kongreseto) happens alongside the largest Esperanto convention, the World Congress of Esperanto (Universala Kongreso).