One of the preoccupations of the middle-aged and older—it’s on my mind, as I mark a significant birthday next week—is keeping the mind sharp. You might have heard of one trick in particular: bilingualism. A pile of studies had seemed to indicate that speaking multiple languages offers protection to the ageing brain. Yet researchers have struggled to replicate those studies’ results. So more recent efforts have been focused on the question of who, specifically, benefits from bilingualism.

The bilingual advantage in “executive function”, involving planning and carrying out complex tasks, seems to accrue most to those who speak a second language fluently, and those who switch languages frequently. That means that while I’m lucky to have stumbled into a bilingual (Danish-English) marriage in young adulthood, my son, a “crib” bilingual, is luckier still.

Does that mean older folks shouldn’t bother? Hardly. All kinds of cognitive training, including games and puzzles, can be good for an ageing brain. And even a halting bit of Spanish or French can help you to make connections with other people. That’s superpower enough to make it worth your while.