> Most people don't realize that a language's accent is a physical thing. Your throat, nose, tongue behave differently when speaking different languages. If you're French, you can't speak English while keeping the same physical arrangement of your mouth and throat than when you speak French.
Interesting theory but as a counterexample in Switzerland in the western side of the country people speak French natively and generally their English accent is way better than the English accent in French people. I think it has a lot to do with the culture of the country; for example the protection of the language is not considered as important in Switzerland as it is in France. In France radio stations have minimun quota for French music, something unthinkable in Switzerland.
Interesting theory but as a counterexample in Switzerland in the western side of the country people speak French natively and generally their English accent is way better than the English accent in French people. I think it has a lot to do with the culture of the country; for example the protection of the language is not considered as important in Switzerland as it is in France. In France radio stations have minimun quota for French music, something unthinkable in Switzerland.