A collection of very interesting experiences…
In 1974 I met an Afrikaans gentleman, Chris Botes, who had lived in England for 15 years before returning to South Africa. He was spending time in Cape Town getting his native tongue back before heading to the rural Transvaal. I remember him telling me how he couldn’t face meeting his family as he was no longer fluent and his father wouldn’t be too happy…
Forty years later it’s something still etched in my mind even though we only spoke for several hours: Like other comments he had lost vocab and grammar structures.
Likewise, I know a French chap who’s lived in Britain for more than thirty years. He listens to French radio to help his understanding, but he has a lot of trouble talking to his mother on the phone, because he’s forgotten so much of his French.
I don’t think it is about losing your native language exactly as the headline implies, more about forgetting certain aspects. When I was was young, I had an uncle Piet who would spend four years at a time in (then) French Congo, speaking French and native languages. It took him normally a week or two to speak ‘normal’ Dutch each time upon his return, or at least our local dialect, to be precise. In my own case, I find myself occasionally lost for words when speaking Dutch, or being corrected on a point of grammar or syntax by family and friends - but those things disappear after spending a little time in the Netherlands and Flanders. Another, related, issue is that a language changes continually, and if you lose contact with the language community for a while, you’ll find that vocabulary and expressions have changed, and it takes a little while to pick that up.
All these experioences are a bit “I was a concert pianist, then I became a farmer for 20 years, and I can no longer play some of the more complicated pieces”… Hardly a surprise!
But maybe it is a surprise that something as seemingly fundamental as a mother tongue needs to be practiced. Of course, as a Welsh speaker, I often speak with people who are only confortable with some usages of Welsh because they “haven;t used formal Welsh since school”, or “only ever speak Welsh, never wirte it” etc.
I remember when I was teaching In Japan having conversations with other English teachers about words we couldn’t think of. The only one I can remember is “closet” which you’re just as likely to forget living in the UK.
My English was dreadful after spending five years of teaching in Japan and only speaking English with English learners. But it’s similar to moving to South Wales and picking up regional colloquialisms such as “I wants…” or “I likes…” or “Where to are you?”