Can people forget their native language after not speaking it for a long time? The official term for the process of forgetting one’s native language is “first language attrition”. In contrast, “language acquisition” is the process by which someone learns a new language and can refer to either the native or a second language.
To answer the above question, BBC Magazine asked readers under which circumstances a person could lose their native or first language. From the answers received, it seems rare that people will lose permanently and completely their mother language. It is just easier for them to speak the second language they have been speaking regularly. It is not certain to what extent and how long it will take for the mother language to return. Age, degree of immersion or interference from the second language, brain injuries and emotional trauma might be some factors responsible for language loss.