Suppose I am really serious about following the path of Vajrayana Buddhism o the point of studying texts in their original and I speak only English. I assume that the best language to learn would be Tibetan. Is this correct? What other languages would be relevant for this?
For example, if you would like to study the various forms and schools of Christian thought, I would recommend learning mostly Greek, Latin and Hebrew, but also some Aramaic, Russian and German, in their ancient versions.
If, instead of Vajrayana, I wanted to follow the path of Mahayana, I would assume some kind of ancient Mandarin was the way to go. I assume that this is analogous for Theravada and Pali.
For each school of Buddhism, what would be the best languages to learn in order to be able to study the bulk of the canon associated to that school in its original and why?