DD is bilingual. It's possible that we'll move to another country some day, and I'm worried she may end up forgetting one of her first languages.
One of her languages is English, so I'm not worried about her losing that, but the other language is rare and not spoken anywhere but where we live now. Of course we'd do what we could to keep it up, but I'm not perfectly fluent in it, and I'm not sure whether just DH speaking it would be enough.
I have two close friends who migrated & switched languages at 5 and 7 years old, and neither of them speak a word of their first languages. :/
Does anyone have any experience with this? From what age is a child unlikely to forget their native language if it's no longer spoken around them?
Mama to a preschooler and a baby.
Dh is the only one around dd who speaks L2. I don't speak either of his two native languages. It can be done with perseverance, but your fears are well-founded. The key is that you absolutely HAVE to continue speaking L2 at home.
When we moved from Germany back to the US, dd lost her German. It was L3 for her at the time, but she was quite fluent, as all of her friends were German. When we returned to the US, she went on to go to an immersion school in a different L3 and we didn't speak any German at home, so she lost her German. It's completely gone now, but for passive understanding of some of her favorite cartoons. Like I said, though, we were bilingual at home in two other languages (OPOL method), not German, and did not try to actively help her with her German. We would have loved to put her in German immersion, but there were no German immersion schools where we live, just Spanish and French. (She's in Spanish immersion, so not even a Germanic language.)
As for when they forget languages... if you do some research on something called "The Critical Period Theory", which I (as someone with an undergrad degree in linguistics) believe is accurate, then it's about puberty when kids really have the language hardwired into the brain. I would not let up on a language until a child gets all the way through puberty if you want them to be fluent both actively (speaking) and passively (understanding). Good luck!