By the time I first became interested in learning English, I had already taken several classes on it at my primary school. In north-western Argentina it’s a common expectation to be taught a second language, but hardly anyone expects actually to learn one. After six or seven years, I could name the different rooms of the house, about ten colours, and a few common household pets. If the grey cat didn’t happen to be in the dining room, my conversation would have been uninformative. And as far as verb tenses go, all my communicable existence occurred in an interrupted present, without memory of the past or plan for the future.

My ignorance wasn’t part of a general aversion to, or lack of interest in, languages. When I was six my mother taught me a little Latin and Ancient Greek, and we used to attempt poetry translations with more ambition than competence. Even when our lack of proficiency frustrated the finding of the precise equivalence, the beauty of the texts would shine through.

Three years later I turned my interest towards Quechua, one of the languages of the Inca civilisation. It hadn’t been significantly spoken in the region for centuries, but it had left its mark in place names. It also remained the source for expressions of emotion: tenderness and expletives alike kept the old tongue. It hadn’t been a written language so no texts remained to fix a formal lexicon, and the sparseness of speakers made differences in pronunciation marked.

To a greater or lesser extent, all the ...