Linguistic nuances, Part I

It is true that I don't very well know how to answer the question, "so how good is your Dutch?" Mostly I talk about how my Dutch SHOULD be better than it is, after almost seven years. All my other languages were better after this amount of time. Even when I say that my Dutch is "serviceable, but not fluent" it means different things to different people, depending on what your standards are for "serviceable" and "fluent".

I once talked to someone about how long it takes to "think" in a language, and she said that she was able to think in Spanish after a few months in Colombia. I'm not sure if she's linguistically much more gifted than I am, or if we have different ideas of what it means to "think" in a language. I don't just mean "carry internal dialogue in a language", I mean "realizing that your subconscious thought patterns, when analyzed, conform to the linguistic structure of said language." Some people say that dreaming in a language is a sign of fluency, but I don't buy that. I know many people who dream in a language they've only started learning, simply because their mind is occupied with it.

I can't call my Dutch "fluent" because there are too many nuances that remain hidden to me. I wrote a Dutch eMail the other day and, wanting to be sure, had it proof-read by a friend. The friend told me that (just as I suspected) the grammar and content was fine, but the TONE was more aggressive than I probably intended. "Fluent", in my book, is someone who can use the words and grammar not only to convey a message, but to convey it well, with the intended emotional tone. Many people who say offensive things aren't really itching for a fight, they're just not particularly articulate. A non-native English speaker may use words like "slim", "skinny", "thin", "narrow" and "slender" interchangeably; a fluent English speaker knows how the shades of difference between these words can determine the tone of a conversation. Also, a fluent English speaker knows that you can talk about a narrow creek or a slender bridge, but when someone mentions a skinny creek or a slim bridge, it calls their fluency into question even though very few people really know the grammatical rules governing these adjectives and nouns. It just FEELS odd to think of a creek being "skinny". On the other hand, intentionally creating that oddness for effect can also be the mark of a great word-smith.

Or am I confusing "fluency" with "eloquence" here? Some native speakers have trouble with nuances as well, but even though you could say they're not eloquent, can you accuse them of not being fluent? There is a line of division there somewhere, and it's somewhat hazy.