source: https://www.scotthyoung.com/blog/2013/11/22/language-switching/


  • learning a new language can interfere with your ability to speak the old ones
  • interference is more noticeable when the languages are similar or related
    • it requires a higher effort to keep them separate
  • most significant also when speaking vs. understanding
    • the retrieval process in the brain is maybe more “active” for the former (speaking)
  • it’s a bit like muscles, you don’t really lose them once you’ve built them, muscle memory persists
    • but you have to re-train those language muscles to restore them
  • the more you practice switching between languages, the lower the interference / friction
    • over time, it’ll be easier to handle multiple languages
  • higher proficiency suffers less from interference and forgetting