How do you know when you're fluent in a language? I was having this conversation with a friend of mine today and we concluded that it would be cool if there was some kind of 'bilingual test', such as, calling a person from that nationality on the phone & pretending to be raising money for charity, or, being able to rap in that language... or my favourite, was posing as a 'telephone psychic', because it uses a lot of the things people usually learn in languages, such as ages of family members, etc... any thoughts?