Most of us heard about such levels as Beginner, Intermediate, Upper Intermediate, Advanced.
As I understand "Fluent" is the highest level when describing someone's English.
But how would you describe it? Some people think that "Fluent" is just when you speak very good (relative to other non-native speakers). But I think this is not enough. I think that you can say that you speak fluently when it is hard for native speakers to understand (based on your speech, accent and grammar) that English is not your native language. And if a native speaker can quickly (matter of seconds, or a minute) understand that your are a foreigner - you don't have a fluent level.
What do you think?