Can You Unlearn A Language?

And if so, how do you get it back?

Laura Simmons - Editor and Staff Writer

Laura Simmons

Laura Simmons - Editor and Staff Writer

Laura Simmons

Editor and Staff Writer

Laura is an editor and staff writer at IFLScience. She obtained her Master's in Experimental Neuroscience from Imperial College London.

Editor and Staff Writer

man wearing headphones with mouth open as if speaking, with illustrated flags from different nations to represent multiple languages

It’s definitely possible to lose fluency in your native language, but research suggests you’re unlikely to forget it altogether.

Image credit: pathdoc/

How much of your high school French do you remember? Maybe enough to order a drink or ask where the library is? For most people, studying a language at school doesn’t allow them to achieve true fluency, so it’s probably not surprising that you’d start to lose those skills if you don’t practice them. But what about your native language? Is it possible for someone who is bilingual or multilingual to unlearn their first language?

The short answer is… kind of. It’s certainly possible to forget a lot of the vocabulary and grammar that once came naturally, through a process known as language attrition.


What is language attrition?

One leading researcher in this area is Professor Monika S. Schmid, a linguist from the University of York in the UK. A native German speaker, Schmid describes her own experiences with language attrition on her website. Some of the common signs of this include forgetting specific words, using odd expressions or putting words together incorrectly, and becoming more hesitant when speaking.

It’s very common for people who spend long periods of time learning and speaking a new language to start to have difficulty with their native language – in linguist-speak, the L1. But while this can be distressing, it is unlikely that an adult will completely forget a language they once spoke fluently.

For young children, however, it’s a different story. Children’s brains are much more flexible when it comes to language acquisition, but that also leaves them more vulnerable to completely losing their L1 if they’re in an environment where they’re no longer exposed to it.

One study illustrated this with the case of a Russian child who was adopted by an American family at a young age. The researchers observed how the little girl quickly began to forget vocabulary in Russian, her L1, as she was learning the same words in English. 


Language attrition in adults affects different people in different ways, and there are lots of sociological and psychological factors at play. For example, someone who has to leave their native country due to war or persecution may simply not wish to use their L1 again, something that Schmid studied with respect to German Jews who fled the Holocaust

But there’s also some interesting neuroscience underlying all this. Humans are some of the only mammals capable of true vocal learning. The best model animals we have to study this are songbirds from the order Passeriformes, which includes many of your familiar garden visitors like finches and sparrows.

It’s been suggested that the brain pathways underlying human vocal learning are very similar to those that exist in the songbird brain. Birds have a system of two circuits involving different brain areas – one that’s active when they’re first learning their distinctive song, and one they use later to reproduce the song once they’ve learned it. 

In humans, so the theory goes, we have a similar vocal learning circuit that’s active in babies and children as they learn to talk. But when you go to learn a new language later on in life, the balance between the two brain circuits has shifted, and the vocal learning circuit is effectively switched off at a much earlier stage. In other words, we can’t recapture the same processes we used to learn to speak for the very first time.


This means that by the age of about 12, your L1 has become crystallized - you might forget words and phrases that you don’t use anymore, but you won’t truly forget the language as a whole. This also helps explain why it’s often difficult to lose an accent from your native language, even if you become highly skilled at a second or third language as an adult. 

Can you stop language attrition?

Schmid highlights that there has been a dearth of research into language attrition, which is somewhat at odds with how upsetting it can be for people, and the negative reactions they can face. She cites numerous examples of personal testimonies where people discuss their difficulties around losing their L1 proficiency.

Fortunately, there are some things you can do to help prevent or reverse language attrition, although some of them might seem counterintuitive.

One thing that might seem like an obvious solution would be to ensure you spend time speaking to others with the same native language as you, to keep practicing as much as possible. In reality, this can have the opposite effect, as linguist Laura Dominguez explained to BBC Future


Dominguez noticed that Cuban immigrants living in a largely Spanish-speaking community in Miami had lost some of their native grammatical structures, more so than a group of Spaniards living in the UK and speaking mostly English on a daily basis. Dominguez concluded that this was because the Cubans were communicating mostly with Colombians and Mexicans, and so had taken on traits from these different variants of Spanish, something that she thinks happens more easily with languages or dialects that are very similar to our own.

Indeed, the prevalence of multilingualism in Miami is such that recent research has shown how an entirely new “Spanglish” dialect is forming in the region. 

Most researchers seem to agree that one of the best remedies for language attrition is a trip back to one’s native country, where full immersion in the language normally helps to reawaken those skills. But Dominguez stressed that attrition should not necessarily be a cause for alarm.

“Attrition is not a bad thing. It’s just a natural process,” she explained. “These people have made changes to their grammar that is consistent with their new reality.”


Language is constantly evolving. Accents and dialects change and morph over time. Feeling like your L1 is slipping out of your grasp can be a difficult experience, not least because of how one’s native language can be tied up with feelings around identity and heritage. 

But it’s comforting to know that once a native language is established, the research suggests that it can’t be truly lost. And the fact that our speech and language use can change and adapt to our circumstances isn’t really something to be feared – it’s part of what makes us human. 


  • tag
  • language,

  • neuroscience,

  • vocal learning,

  • speech,

  • linguistics,

  • Language learning