I have been away from my native city, Calcutta, for 40 years thanks to my work as an international executive and civil servant and, later, a diplomat. When I now visit Bengal, I find I am the only person in a room speaking Bengali - a language I have rarely spoken in four decades. The others, although native residents, speak a strange hybrid of Bengali and English. This curious patois is so nearly universal in Calcutta that it passes today as the rubric of spoken Bengali. The experience is disconcerting.

I have spent a large part of my exile in English-speaking countries, principally the US. With so many large immigrant communities, English here has assimilated many foreign words, particularly from German and French. Yet, when a person of German descent speaks English in the US, he or she never imports a word from German. The French would rather jump from the top of the Eiffel Tower than import English words in a French conversation.

Who mixes languages? Half-literate Mexican immigrants who don't know the English words for many new things they encounter in their new country. The Salvadoran woman who cleans my house often starts to speak in English, finds herself at a loss of words, and resorts to a Spanish phrase. Are the Calcutta residents then, like these Hispanics, half-literate in Bengali and need the crutch of English words? Or is their command of English so limited that they need a frequent recourse to Bengali?

Last year, I visited a school in Calcutta I had attended years earlier, where everything was taught in Bengali. The principal told me that his school, like other schools that taught in Bengali, was under popular pressure to teach in English. He said that only the poor now send their children to Bengali-medium schools. This led me to ponder if, in subsequent visits to Calcutta, I was likely to encounter even a smaller percentage of Bengali words in the hybrid language one now hears in Calcutta.

It has not impeded my fluency in English, let alone in Spanish or French, that I learned everything in Bengali while in school. I confess to being influenced instead by a Bimal Roy film, where the protagonist, asked why he never uses an English word while speaking Bengali, says, "I know both the languages. I don't need to combine one with the other."

The current crop of Bengali movies I have been reviewing in Washington alerted me to the class distinction film directors are delineating. It is the plebeians in the movies, the cooks, domestics, workers and chauffeurs, who speak consistently in Bengali, whereas their bosses, the elite class of executives, doctors, engineers and bureaucrats, cannot open their mouth without spouting inane English phrases. Ineptitude in idioms seems almost flaunted as a hallmark of aristocracy.

There is nothing aristocratic in losing or corrupting one's mother tongue. Rather evidence suggests it is crippling for humans if they can't function in their mother tongue, the language they grew up with. They lose the critical elements of ingenuity and creativity.

I recently returned from Ireland where the British rulers, as in India, imposed English in brutal suppression of Gaelic. You could no longer use the local language in courts or offices. Now, after independence, the country has wisely decided to revive the language and the signs are evident on every street and in every museum. Even the leader of the country (curiously, from an Indian family in Maharashtra, just where I was born) is called Taoiseach instead of prime minister. Last year, I was in Israel, whose population includes Jews from every corner of the globe, and I was astounded to find that 91 per cent speak Hebrew and 72 per cent speak it fluently - a language that was consciously resurrected after 1,500 years of near-complete disuse.

For concerned parents who imagine that they are helping their children's careers by getting them to learn an 'international' language to the exclusion of their first language, there is also a powerful lesson from current brain researchers. It appears that we learn different languages with different parts of our brains; and research suggests that children develop their mental capacities better when they learn an additional language along with their mother tongue. Bengali students would do better for themselves were they to learn Bengali well and, alongside Bengali, learn English well too. Struggling with a turn of phrase, when I write in English, I remind myself that three of the greatest masters of the English language, Conrad, Nabokov and Rushdie, did not have English as their first language.

History shows that languages, like empires, rise and fall. Hebrew is just one remarkable example. Let it be said that Bengali, a language with a rich tradition, flourished in our time and not entered a phase of undetected decline.