A first language (also native language, mother tongue, arterial language, or L1) is the language(s) a person has learned from birth or within the critical period, or that a person speaks the best and so is often the basis for sociolinguistic identity. In some countries, the terms native language or mother tongue refer to the language of one's ethnic group rather than one's first language. Sometimes, there can be more than one mother tongue, (for example, when the child's parents speak different languages). Those children are usually called bilingual.
By contrast, a second language is any language that one speaks other than one's first language.
Read more about First Language: Terminology, Significance, On Multilinguality
Famous quotes containing the word language:
“In a language known to us, we have substituted the opacity of the sounds with the transparence of the ideas. But a language we do not know is a closed place in which the one we love can deceive us, making us, locked outside and convulsed in our impotence, incapable of seeing or preventing anything.”
—Marcel Proust (1871–1922)