I´ve been living in Russia for 2 years. Recently i went back to home for a visit and i was surprised that my family and friends told me i now speak Spanish with a weird accent, kind of foreigner accent.
I cant say im a polyglot, i speak Spanish and Catalan as a native languages and English and Russian as a second languages. But when i speak English or Russian, i always have a thick Spanish accent, thats why it was so unexpected to hear that i dont have Spanish accent in my own language anymore.
Yes, it often happens. My friend has been living in Sweden for 20 years. And I feel that her Russian is a bit like a foreigner language because sie immerses every day in sounds which are different from Russian, and it influences her Russian as well.
You can lose your native language.
“Age is a factor. Once past puberty, Dr Schmid says, your first language is stable and the effects of attrition can reverse themselves if you are re-immersed. But children as old as 10 don’t necessarily retain the language they were born into.”