Whenever i see, in a resumé (C.V.) for example, that someone is 'fluent' in a language other than their mother tongue. I think "O RLY". Color me skeptical, but I'd say 80% to 90% of the people who have said they are fluent, really aren't according to my standards.
Some years ago when I was working in a soul-crushing job for a Japanese company, I was introduced to this young American dude in a suit who said he was "totally fluent in Japanese". I had to sit and talk to this dude for at least 10 minutes. Let me say, I understood him for about 60 seconds worth out of the 10 minutes. The rest I had to sort of extrapolate.
Eventually I gently maneuvered him into English because my head was hurting. (At least I think I was gentle. Or I may have said "Can we switch to English? My ears are bleeding." It was some time ago.)
Then there was another time when this man who a friend of mine was in love with (or, to put it another way, my friend had a man crush on the guy) brought his overly smart and slightly creepy kids to a group dinner. His daughter was seated next to me. At some point the girl (she was about 16) turned to me and started babbling. I remember staring at her blankly. Her father beamed at me, saying "Isn't her Japanese great?" I think I nodded sort of semi-consciously, not wishing to offend him or crush her spirit, or whatever. It sounded as Japanese to me as Dutch sounds German. (If someone who speaks German listens to Dutch, it almost seems understandable, like if you listen hard enough you'll eventually get it. But you never do. There's a sort of similar-but-really-different quality like that with Korean vs. Japanese too.)
There are a couple of criteria that I think anyone has to meet before they can say with total honesty and without delusion that they are fluent.
- You should be able to be understood by a native speaker. Kind of obvious.
- You should be able to converse more or less without thinking too much. You may get stuck on a few words but otherwise, it should flow.
- You should be familiar with at least some slang terms or idioms.
- You should dream in that language, at least sometimes.
The last one is the most important. Once you start to hear and speak that language in your dreams, it means that language has penetrated deep into your brain.
So, according to these criteria, I am really only fluent in Japanese, my native language, and English, though I do sometimes dream some German. When I'm in France for some length of time I dream a bit in that too but - no way am I fluent in French of German. I get by and that's it.
I am not sure that I helped that girl speaking gibberish to me by nodding when her proud parent said how great her Japanese was. I would think honesty would be better. But I wasn't about to ripple the waves with virtual strangers at dinner, especially with a kid.