A reader asks, in regards to my no longer living in China:
“i always wonder what changes in a person when leaving china after many years .. has your chinese rusted at all?”
Yes and no. I find that right when I get off the airplane in China, my spoken Chinese lags terribly for as much as a week, but after that it all comes back and I am up to about 95% of what I was before. The longer the trip, the better it gets, and sometimes it surpasses where I was in China.
Environment is everything with spoken language, and when I was living in China my Chinese wife insisted on using English with me, as did my son. My colleagues at work were frequently that way as well, as were most of my clients. With the family in California, I spend more time speaking Chinese on my trips to China than I did when I was living in Beijing. Counter-intuitive, perhaps, but true.
My reading and writing have improved. Being away, I find myself seeking out social media and news more to keep myself plugged-in, so I read and write in Chinese more now than I did when I was living in China.
NB: I think we underestimate the lasting effects of long term immersion. As I have found with my Spanish (which lay unused for nearly three decades) the tongue becomes a dull knife without regular honing, but the blade is still steel. The longer you’ve been away, the duller it becomes, but once you are back in the linguistic environment, the blade begins to sharpen, and it all soon returns. I would probably need a month or two in Madrid or Mexico City to get my Spanish back up to where it was in May of 1985, but a week usually suffices for Chinese.