“TELL me, why should we care?” he asks.

It’s a question I can expect whenever I do a lecture about the looming extinction of most of the world’s 6,000 languages, a great many of which are spoken by small groups of indigenous people. For some reason the question is almost always posed by a man seated in a row somewhere near the back.

Asked to elaborate, he says that if indigenous people want to give up their ancestral language to join the modern world, why should we consider it a tragedy? Languages have always died as time has passed. What’s so special about a language?

The answer I’m supposed to give is that each language, in the way it applies words to things and in the way its grammar works, is a unique window on the world. In Russian there’s no word just for blue; you have to specify whether you mean dark or light blue. In Chinese, you don’t say next week and last week but the week below and the week above. If a language dies, a fascinating way of thinking dies along with it.

I used to say something like that, but lately I have changed my answer.

Certainly, experiments do show that a language can have a fascinating effect on how its speakers think. Russian speakers are on average 124 milliseconds faster than English speakers at identifying when dark blue shades into light blue. A French person is a tad more likely than an Anglophone to imagine a table as having a high voice if it were a cartoon character, because the word is marked as feminine in his language.