Oddly enough, when I became moderately fluent in Chinese-for-kids, I lost the ability to manage even basic phrases in any other language (besides English). I'd try to say something simple in Japanese, French, or Spanish, and it would come out in Chinese. Most unhelpful. My very limited facility in those other languages has gradually returned. I think it was kind of like "replacement monolingualism" when adopted or immigrant kids completely lose their first language in the process of picking up the new language, only it happened with my non-first-language.
