Additionally, the term
native can be misleading. It is quite possible that the first language learned is no longer a speaker's dominant language. Young immigrant children, whose families have moved to a new linguistic environment may lose, in part or in totality, the language they first acquired.
In such cases, competence, function, as well as origin are taken into consideration:
Origin: the language(s) one learned first (the language(s) in which one has established the first long-lasting verbal contacts).
Competence: the language(s) one knows best.
Function: the language(s) one uses most.
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