List of Languages by Distance of Usefulness?
People make lists of languages by number of speakers, but instead, I'm interested in ranking languages by distance—how far (or to how many countries) one can travel while that language is still useful (either that specific language is used, or a related language such that much can be parsed as with Spanish and Portuguese). This is different than number of speakers, since while Mandarin might have the [2nd highest number of speakers](https://en.wikipedia.org/wiki/List_of_languages_by_total_number_of_speakers), the vast majority of them are likely from China, meaning it might rank very high in terms of number of speakers, it wouldn't rank quite as high by distance.
It seems clear to me that English would be at the top for ranking by distance, since it is becoming a global lingua franca, but what would be the languages after that? My best guesses would either be Spanish (much of South America, plus Spain, and you can probably still pick some stuff out in French or Italian), Arabic (much of the Middle East and N. Africa, plus Muslims living around the world who learn Arabic religiously), or Russian (probably many cognates with the other Slavic languages).
What would you pick?
It seems clear to me that English would be at the top for ranking by distance, since it is becoming a global lingua franca, but what would be the languages after that? My best guesses would either be Spanish (much of South America, plus Spain, and you can probably still pick some stuff out in French or Italian), Arabic (much of the Middle East and N. Africa, plus Muslims living around the world who learn Arabic religiously), or Russian (probably many cognates with the other Slavic languages).
What would you pick?
