Sometimes, it is the little things in life that make you understand the big things. For me, the tiny slip of paper inside Kinder Surprise Eggs is a reminder of something important that I — and we — have lost.

That something is language. The slip of paper contains a brief warning message warning that the toy is not suitable for children under three years old — in 34 languages. While the warning message is translated into tongues as various as Armenian and Arabic, there isn’t a Jewish language among them…

Among the many things Jews have lost in the modern world are our languages. Of course, we still study Jewish texts in their original Hebrew and Aramaic and the (re)creation of Ivrit remains an extraordinary achievement. But there was a time when it was common for Jews across the world to speak a uniquely Jewish vernacular alongside the common tongue of where they resided. Outside the Haredi world (a big exception, it is true) where Yiddish is still widely spoken, Jewish vernaculars are no longer the norm.

My family’s story is common in the UK: my Yiddish-speaking great-grandparents emigrated here in the late 19th century. Their children grew up speaking English but had a passive understanding of Yiddish. My parents and myself know a few words with which we occasionally spice up our conversations. This story is also common — although not exclusive — to today’s Jews who are descended from speakers of Ladino, Judeo-Arabic, Bukharian and many other tongues. Part of the reason for this is, of course, the Shoah, which wiped out millions of speakers of some of these languages. In some quarters it is common to blame Zionism as well, which — so the argument goes — disparaged the distinctiveness of Diaspora Jewish cultures and sought to replace them with a common Hebrew-speaking one. While the situation in Israel may be more complicated than that (it remains a last redoubt of some Jewish linguistic communities), it is certainly true that modern nation states have often devalued linguistic diversity and everyday multilingualism.

Just as my grandparents were taught to speak the King’s English and to eschew the bi- or trilingualism that their ancestors in Poland would have known, Welsh and Scots Gaelic speakers were being punished in schools when they spoke their own languages. Across Europe, regional languages were being suppressed as the centralising modern state sought to institute a standardised common tongue. This was not a uniform process of course. Compare the parlous state of Occitan in southern France, a language with a rich literary history that is now spoken only by a few tens of thousands, with the closely related Catalan language in Spain, which is spoken by millions and is the language of regional government.

So the loss of Jewish linguistic diversity is far from a unique process, even if it has distinctive features. Linguistically, the human race is heading towards a mass extinction event. Some estimates suggest that, by the end of the century, 90 per cent of the world’s languages will lose their last native speaker, leaving us with a few hundred at best. Unesco’s Atlas of the World’s Languages in Danger lists near 2,500 endangered languages. When a language becomes extinct, we do not just lose its unique sounds, words and grammar but also something just as precious, the intrinsic connection between a people’s culture and a people’s way of communicating. The reasons for language extinction are many, ranging from genocide and active suppression to more subtle pressures such as the mass media. Another factor is the forgetting of the fact that human beings are capable of being multilingual. Throughout history everyday multilingualism has been the norm in many parts of the world and it still is today in some parts of Africa and Asia.

Yet modern education systems have often seen a second or third language as a threat to the “official” tongue. Yet if the modern world has put pressure on linguistic diversity, it has also given us the tools to promote the revival of endangered or extinct tongues. The astonishing revival of Ivrit is, in part, due to leveraging modern systems of education and mass communication. And that effort, while it was accelerated once Israel was a nation state, was well under way decades before independence. So other peoples who do not have their own nation states have learned from the revival of Hebrew. In Wales, for example, an intensive course in Welsh is now known as a wlpan. The Israeli-born linguist Ghil’ad Zuckerman has applied the lessons of Ivrit to language revival among indigenous Australians, many of whose languages are either extinct or endangered.

Diaspora Jewish languages have their own activists dedicated to their revival or, at least, documenting and teaching them before they completed die out. Outside the Haredi world, Yiddish has long had a vigorous community of speakers and learners who draw on the language’s vibrant literature and history. In the UK, the recent foundation of the Oxford School of Rare Jewish Languages has, for the first time in this country, began to offer classes in both Baghdadi and Classical Judeo-Arabic as well as other rarely taught tongues such as Judeo-Italian and Judeo-Tat. The internet is a boon to the study of language, with the popular Duolingo app now offering lessons in Yiddish and technologies such as Zoom mean that even the smallest language can find a community of learners worldwide. Yet I can’t help feeling that revival means ensuring that languages are used in the most prosaic contexts. It’s all very well studying Yiddish in order to read Shalom Aleichem, but the heart of a living language is its use in mundane contexts — and here we come back to the warning messages in Kinder Surprise Eggs…

The languages found on product packaging are almost always the official languages of nation states. So a Kinder Egg bought in Israel will feature a Hebrew warning message (it doesn’t appear on the multilingual warning message sheet found in Kinder Eggs in the UK) but a Kinder Egg bought in Wales will not feature Welsh. And even though Yiddish is the everyday vernacular of hundreds of thousands of Haredim worldwide, it is almost never used on product packaging, although NHS health information in the UK is sometimes given in Yiddish.

In my book The Babel Message: A Love Letter to Language, I sought out translations of the Kinder Surprise warning message into dozens more languages — and those included Jewish languages. I was proud to include warning messages in Yiddish, Ladino and Judeo-Arabic. To see such mundane words in the languages of the Jewish Diaspora gave me a glimpse of what could have been and perhaps could still be — a world in which encountering minority and Diaspora vernaculars would be an ordinary thing.

I also went further, challenging translators to produce versions of the warning message in Biblical Hebrew and Talmudic Aramaic. Yes, that was a bizarre challenge, but it had a serious purpose: Languages, as Ghil’ad Zuckerman has argued, never really die, they only “sleep”. Whilst the translations had to clear some fearsome hurdles — the lack of a word for “toy” being one of them — they also showed that the languages of our most sacred texts can escape that context and become something else entirely. After all, that’s how Ivrit was created.

Keith Kahn-Harris’s The Babel Message: A Love Letter to Language is published by Icon Books on 4 November