FYI This doesn't apply to me personally, but I'm interested and I've been reading a few articles about this recently and I wondered what people's experiences might be with this phenonemon. Some people mistakenly assume that a person's first language will automatically be the language that they have the best command over, but circumstances may dictate that that is not always the case.
For example I'm a big fan of the comedian Louis CK, who moved to the USA when he was 7 or 8 years old from Mexico, speaking only Spanish. And now he sounds like a native US English speaker, and his Spanish is not at a native level. Anyone else have any similar experiences? What about if you moved to the new country as an adult, rather than as a child? I think that if he had moved as an adult he would have retained better command of his Spanish, but its intuitive that if you don't actively use your first language on a regular basis your levels will drop over time.
'Xinjiang ancestry' was not quite correct, as it is a province, not a culture. Let is be 'from Kashgar'...
Paul, alas, with respect to adult migrants my experience is restricted. It is usually Russains who moved to USA. They mainteined contacts with other Russians, and in late 90's they rushed to the Russian segment of the Internet. Worst of all - it is where I know the majority of such people from.
So my observations are biased, at best. Still I never has met a person, that switched language as adult, and had serious problems with mother tongue. Why I would prefer to see stats realated to adult migrants.... It is a nice point of reference.
For children we should somehow assign a level of previous exposure to mother tongue first:/
Not easy thing: for example, my Uzbek friend was bilingual, and even in Uzbekistan Russian is much associeted with education. And he attended Russian school. Russian attracted him since early days because of printed material written in Russian, people he comunicated with etc. I'm not even sure which language his parents (of Xinjiang and Uzbek ancestry) preferred at home:-/
KP When I say 'actively use' I mean speaking and writing, as with these two activities you have to actively construct things to say. I consider listening and reading to be passively using the language which uses a different set of skills. So for example I have read of people who can understand the spoken and written language but their speaking and writing skills decrease a lot if they don't use them for a long period of time. This even happened to my friend, he was bilingual in German growing up and can still understand it when spoken, but he hasn't had to speak it for 15 years and now he can't speak it well at all. He hasn't actively used the language during that time so his level decreased a lot.
Also, the comedian I mentioned earlier moved to the US with his single mother (who was a native English speaker) to Boston in the USA, which in the 1970's didn't have a large Spanish speaking population. Therefore I think his opportunities to speak and read (i.e. actively use) his first language would have been limited back then. The vast majority of his interactions would have been in English, so that became his stronger language. This of course is also in the days prior to the internet, so he wouldn't have been able to practice or have exposure that way.
...and times with a single day...
to be read as "...at least 3 times within..."
Paul, I never met a single person who 'doesn't actively use' his mother tongue.
So what is often observed is 1) some contamination with English 2) one can't remember a correct word.
As about the second, it happened with me 2 days ago. I hand't slept enough and times with a single day could not easily remember how, e.g., to say 'obsessed with' in Russian.
Of course, I'm not starting to forget Russian.
It is just that I used too much of English a day before (and last months in general), and though I'm not proficient in English, there some English words I never checked in the dictionary (means: if exact correspondence exists in Russian, it is not really easy to find them. Whenever I find one, I often get surprised:)). Of course, when I type in English - I think in English, so switching to a Russian person... I still have Enlgish program loaded to my 'operative memory'.
It doesn't address your question directly.