Language Attrition & Code-Switching – What Really Happens in the Bilingual Brain?

As bilingual individuals grow, move across linguistic environments, or shift their social routines, one of their languages can gradually fade. This process is known as language attrition—the loss (partial or full) of a previously acquired language. From a linguistic standpoint, this is not a failure of memory but a dynamic reorganization of the brain’s language systems.

Key Linguistic Insights on Attrition and Code-Switching

1. Attrition supports the modular view of grammar.
Selective loss—such as lexical gaps without syntactic breakdown—reinforces the idea that language components (syntax, morphology, phonology) can deteriorate independently, echoing modular theories in generative grammar.

2. Cognitive control plays a dual role.
Bilinguals experiencing attrition often retain passive knowledge, but struggle with retrieval. This aligns with psycholinguistic models emphasizing executive function and inhibitory control in bilingual language management.

3. Interference and reanalysis are central to early attrition.
Early-stage attrition may mimic L2-influenced transfer, where the dominant language reshapes the weaker one’s word order, morphology, or pragmatics. For example, V2 structure loss in heritage German aligns with L2 English interference.

4. Code-switching reflects sociolinguistic alignment, not loss.
Patterns of code-switching correlate with community norms, identity signaling, and domain-specific fluency. The Matrix Language Frame (MLF) model helps explain structural stability during intra-sentential switching.

5. Attrition data informs theories of language storage.
Cases of rapid reactivation support theories that language is not erased, but inhibited. This has implications for language acquisition models, second language pedagogy, and neural plasticity studies.

6. Heritage language studies are key to attrition research.
Linguistic analysis of heritage speakers—those exposed to a language in childhood but not dominant in it—has become foundational in understanding morphosyntactic attrition, especially in verb inflection, case marking, and word order.

What Is Language Attrition(gradual reduction)?

Language attrition refers to the gradual erosion of a language due to reduced exposure and use. It can affect lexicon (word recall), morphosyntax (grammar), phonology (sound patterns), or even pragmatic competence (appropriate use in context). It may occur:

• In children who stop using a home language after starting school in another

• In immigrants who stop speaking their native language over time

• In adults who move away from language-rich environments

Attrition is not all-or-nothing. It can be selective—for example, a person might forget verb agreement but retain pronunciation. It also doesn’t erase knowledge completely; often, with re-exposure, the “lost” language resurfaces, suggesting the underlying linguistic system remains intact.

Is Language Attrition Permanent?

Not necessarily. Research in neurolinguistics and second language acquisition shows that previously acquired languages can re-emerge even after years of disuse. This supports the idea that long-term memory for language is durable, but access can become less efficient. Studies using fMRI and ERP (event-related potentials) show reactivation patterns in dormant languages, especially when emotional or identity-related triggers are involved.

How Is This Different from Code-Switching?

While attrition is a reduction or fading of language ability, code-switching is an active, intentional choice by bilinguals to alternate between languages. It can occur:

• Mid-sentence (“Let’s go al supermercado”)

• Between sentences (“I’m tired. Voy a descansar.”)

• Based on topic, listener, or social setting

Code-switching is not a sign of forgetfulness or attrition. In fact, it demonstrates cognitive flexibility, pragmatic awareness, and high-level control of both linguistic systems. It often serves specific communicative or emotional functions, especially in bilingual communities with fluid language norms.

What Triggers Attrition?

Several factors contribute to language attrition:

• Reduced input/output: Not hearing or using the language regularly

• Language dominance shift: One language becomes more socially or professionally useful

• Lack of emotional or cultural reinforcement

• Peer and educational pressure (especially in children)

• Age of acquisition and proficiency: Later-learned or less-developed languages tend to fade faster

Importantly, attrition is more likely in productive skills (speaking, writing) than receptive skills (understanding, reading), which often remain more stable over time.

Can Code-Switching Help Prevent Attrition?

In some cases, yes. Strategic code-switching can preserve access to less-used vocabulary or structures. For example, bilinguals might insert a word or phrase from a fading language into their dominant one to keep it “alive” in daily use. This serves both as a communicative tool and a subtle act of linguistic maintenance.

However, exclusive reliance on code-switching without full language immersion may still allow deeper levels of attrition to take place—especially in grammar and idiomatic usage.

Final Thought

The process known as language attrition—some loss of an acquired language is a dynamic reorganization of the brain’s language systems. Language attrition is not a sign of failure—it’s a reflection of how flexible and adaptive the bilingual brain is. In contrast, code-switching showcases that adaptability in action. Understanding the difference between the two helps educators, researchers, and bilinguals themselves approach language loss with empathy and precision. And with consistent re-exposure, even “lost” languages can find their way back.