Right, though I think the long tail is beyond the line between language and culture. There comes a point where additional words are not a matter of understandin

Right, though I think the long tail is beyond the line between language and culture. There comes a point where additional words are not a matter of understanding utterances, but of following culture. Effectively none of the English-speaking world would bother to say "Sochi" without the olympics, but they knew the English language and had enough culture to understand from context that it is a place in Russia which hosted the 2014 winter olympics. If you know enough of the language that you can ask "what's that?" at a non-disruptive rate in conversation (or look it up quickly in a dictionary or encyclopedia), I think that counts as good enough.