Language attrition: the other side of the coin

When looking at language acquisition and learning, we rarely consider the other side of the coin: language attrition. This means a language is disappearing, the speaker can’t speak it as well as before. The speech becomes slow and less complex. Attrition happens, and when a language, even a first language, is spoken less, there are small sign of attrition right from the start. It’s frustrating, especially when one has put in a lot of effort learning a language, for it then to disappear. But: is attrition reversible? What was my experience, especially as I was so immersed in Chinese that I spent less time speaking Danish, Spanish and other languages I used to work in?