Throughout one’s life, their mother tongue is usually the first language they learn, closely tied to their identity and cultural background. As people age, they may find themselves learning other languages due to changes in their living environment, leading to fewer opportunities to use their native language. But can people completely forget their mother tongue?
According to a report from LiveScience, individuals may indeed forget their mother tongue in certain circumstances, such as when they move to a country or region where another language is predominantly spoken at a young age.
Linguists refer to this phenomenon as “native language attrition” or the process of losing proficiency in one’s native language, often attributed to lack of usage.
A common scenario is when children are adopted by foreign families. For example, a study published in the journal Cerebral Cortex in 2003 found that children born in South Korea but adopted by French families at ages 3 to 8, by the time they reached 30, their understanding of Korean was no better than native French speakers who had never been exposed to Korean.
However, Laura Dominguez, a linguistics professor at the University of Southampton, mentioned to the website that the older one is when they move, the greater the chances of retaining their mother tongue, as they have already established a solid foundation in their native language. Therefore, teenagers or adults are less likely to completely forget a language, like how to construct past tenses.
Research indicates that individuals are less susceptible to “native language attrition” once they reach adolescence. This could be attributed to the maturity of the brain beyond that age, making it less adaptable and resistant to change.
Dominguez added that the part of the mother tongue that people are most likely to forget in a short period is vocabulary. For instance, an English-speaking college student studying in Spain for a semester may find themselves needing more time to recall how to express certain words in their native language upon returning home.
However, this doesn’t mean that one forgets all the vocabulary in their mother tongue. They just require more time for their brain to retrieve them, as if sorting through a file cabinet containing two sets of vocabulary. Once fully immersed back into their mother tongue, such as by moving back home, they will regain fluency more quickly.
Furthermore, in the field of language, grammar is less likely to be forgotten compared to vocabulary. A study published in the journal Language Learning in 2023, led by Dominguez and her colleagues, showed that individuals who are native Spanish speakers but learned English as a second language and lived in the UK for over 15 years didn’t alter their usage of present tenses in Spanish, unlike with English.
Similar principles apply when forgetting a second language that one rarely uses, depending on how much was initially learned and for how long.
Antonella Sorace, a developmental linguistics professor at the University of Edinburgh, mentioned how one might be surprised by how much they still remember when revisiting these languages.
However, bilingual individuals, especially those with dementia, may be more susceptible to language confusion and reverting to only using their mother tongue. This phenomenon, known as language reversion, can occur even after a lifetime of bilingualism in the instance of dementia.
Apart from potentially forgetting one’s mother tongue due to relocation, people may also change accents because of moving. This is significantly influenced by the environment one lives in.
Jane Setter, a phonetics professor at the University of Reading, wrote in The Conversation that accents serve as symbols of identity, distinguishing various groups.
For example, someone moving from Australia to the United States for work may consciously or unconsciously adjust their accent to be accepted by the new community, improve communication clarity, or avoid potential ridicule due to their accent.