In my experience , both as teacher and foreigner (I live in Germany) ,
however good your command of a language, you only feel really at one
with yourself in your native language.In role playing exercises at a
seminar, in which I took part in English, German and French, people
commented on how differently my personality came across in the various
languages.

As regards Standard BBC pronunciation or similar, I think it depends
who you are teaching and more to the point for what purpose. As a
teacher trainer, my students obviously need to be good models for their
future pupils-whereas a businessman needs intelligible communication
skills but does not necessarily need to be so accurate. In my own case,
now I no longer need to impress in German,I notice that my near-native
German pronunciation has markedly more British elements than it used to
have. A similar thing has also happened to a Spanish friend.

angela Sprotte