A genie offers to make you fluent in twenty or a hundred languages, living or dead. How do you choose?
The greedy algorithm: add whatever language most increases the number of people, living or dead, with whom you could have (had) a fluent conversation; repeat.
Alternately, the language preferred by the most recent ancestor with whom you cannot already converse; repeat. (Closely related dialects come at a discount.)
But I’d trade some slots on either of these lists for some smaller languages of historical or literary interest, such as Etruscan and perhaps Volapük, plus sign languages (ASL, Plains, BSL).
I wonder what Celtic language would be highest on the “greedy” list. Perhaps Irish as spoken at the moment when it ceased to be the majority language of Ireland.
My ancestor list begins with Norwegian and Swedish, but what’s next? Perhaps Gaelic or Welsh; perhaps Saami or Finnish. I would be amused if it could be certainly established that my last non-Germanic ancestor was also non-IE.
You can find some answers that people gave to this question at the comment thread, plus the original blog post with David Madore’s answers.
I hope you don’t mind that I converted your bare URLs to active links. —Anton
David Madore introduces a clever feature: the genie promises at least one and no more than fifteen, without telling you exactly how many (until you use them up), so you must make an explicitly ranked list.
Here are my top twenty, ranked by vague and probably conflicting criteria.
• American Sign Language.
• Japanese, because it’s pretty, and for the movies.
• Lojban. For a scifi language I’d relexify Lojban with Japonesque phonotactics.
• Proto-Italo-Celtic, if the Italo-Celtic hypothesis is true.
• Whichever language was understood by the greatest number of people in the New World before 1492.
• Classical Chinese.
• Classical Arabic.
• Proto-Malayo-Polynesian, to avoid choosing among its living descendants.
• Whichever language was understood by the greatest number of people in trans-Saharan Africa before European (or Muslim) contact.
• Classical Gaelic.
• Hindi, for the movies.
• Finnish, partly because I have several discs of songs in Finnish; partly because of Tolkien.
• Middle High German, as in the Carmina Burana, just because I like its flavor.
• Whichever Chinese language is most spoken outside China+Taiwan.
• Etruscan. I would publish it as my own conlang, heh. If I make no claim to have deciphered Etruscan, no one will question me until it’s too late.
• Plains Sign Talk.
• Volapük. (I already have rusty Esperanto.)
Yet another idea. Starting with an adjacency table of all humans ever, with nonzero for pairs who had a conversation, find topological coordinates for each person in three or four dimensions. The languages used on the convex hull will, I expect, be those least affected by imperial languages. You might choose from these; or you might prefer to strip away the people who spoke only these peripheral languages, repeating until a conveniently small number of core languages remains.
I expect the core to consist of imperial languages (Latin, Arabic, Chinese, Spanish etc) and/or the most prolific ancestors of languages. Or maybe the innermost is like Albanian, with multiple layers of superstratum influence from successive conquerors.
Or: greedy sequence, but alternating between number of speakers and number of readers as the criterion.
Or: greedy sequence, but inversely weighted by world population at the time.
Insert a few with exotic phonologies. Which language distinguishes the most consonant phonemes? The most vowel phonemes? The most tones?