The answer stares us in the face. Like much that does so, it is widely overlooked. But it struck me forcibly in Africa this week (and I bet it will have struck Gordon Brown) as I sat in the back row of the Grade 1 class at Digum Complete Elementary School, by the side of a dirt road nearly 1,000 kilometres north of Addis Ababa in the Tigra region of Ethiopia.

This country, you will recall, was for many centuries a remote and independent African kingdom whose only colonial experience was as an Italian possession for a short period before the Second World War. The British never came here much. Ethiopia is in nobody’s “sphere of influence”.

My class at Digum school were aged between five and seven: 44 boys and girls, some barefoot, some decently dressed, many in rags; some fit and healthy, some with sores or burns, or eye problems. Few would ever have been to Addis Ababa. None had seen another country and few ever will. None will ever have been in a lift or seen an escalator. Some will not have entered a two-storey building. Most will never have made a telephone call and some will never have seen one taking place: a fascinated crowd gathered as I made a satellite call from our campsite to The Times. None will ever have had a television, though some of their parents will have owned a radio and all of them will have listened to one.

The children were divided into a morning shift and an afternoon shift. Thus did their impressive headmaster, Mr Getachew, and his 30 staff, manage to run a school of 1,644 children housed in six long single-storey cabins scattered over an acre of dust.

I had arranged my visit quite by chance. Our guide thought we would be welcome, and we were. Every child stood as we entered a class. “George Bush and Mr Tony Blair will never visit our school,” said the Grade 8 teacher, Mr Hailay, “so you are our most important foreign visitors.” He should invite Mr Brown.

The Grade 1 classroom where I sat had no teaching aids at all, save tiny wooden benches and single-plank desks, dog-eared newspaper-covered exercise books, a blackboard, and a keen and patient young teacher, Mr Hadush. Discipline was absolute.

“Let us sing, children” said Mr Hadush. “Come to the front Abraham.” A tiny boy marched confidently up, all the others rapt. “This is the way I wash my face, wash my face, wash my face,” shrieked Abraham, making face-washing motions with his hand. “This is the way we wash our face,” shrieked all 44 tots, in an ear-splitting chant, “Early in the morning!”

There is no piped water in Digum — just a well with a hand-pump, down by the dried up river.

“This is the way I put on my clothes, put on my clothes, put on my clothes,” shrieked Abraham delightedly, doing the motions. “This is the way we put on our clothes.” Yelled the class, full of excitement at learning and at showing off their learning, “Early in the morning.” Some of them barely had any clothes.

Mr Hadush called a little girl, who looked about five, to the blackboard and handed her a stump of chalk. She wrote out the English alphabet perfectly on the blackboard. Ethiopia’s native script, which she also knew, is composed of the bewildering symbols of Amharic.

The spread of English across the globe is a seismic event in our species’ history. It is one of the biggest things to happen to mankind since the dawn of language. Speech is fundamental not just to communication but to the process of thought itself. No single language has ever before approached universality. English is now doing so. No other language has ever advanced as far, as fast, as ours. This is the first time in history that it has been possible to denote one language as predominant.

Within the lifetimes of Times readers, every other serious contender for that status has been eliminated. French is dying outside France. “Francophone” Africa is turning to English. Portuguese Africa is abandoning Portuguese. German made a small, temporary advance across emergent Eastern Europe but elsewhere outside Germany it is dead. Russian, which we once thought we would all have to learn, is finished. The Japanese are learning English, and developing their own pet variant. China will resist, but Mandarin and Cantonese are not advancing beyond their native speakers. More of the world’s new Muslims are learning English than Arabic. Spanish alone is raising its status and reach — but among Americans, who have English already. India is making an industry out of English speaking, as call-centres daily remind us. A quarter century ago, as the dismemberment of our Empire neared completion, we might have thought that the predominance of our language had passed its zenith. It was only dawn.

It is imponderable what may be the consequences of the advance of this linguistic tide. Within a few generations and for the first time in the story of Homo sapiens, most of our species may be able to communicate in a single language.

The advantage lent to us British by our fluency (and that of the Americans) in this world language should not be exaggerated. The number of native English speakers may not grow much; our relative influence may decline. They know little of us in Ethiopia. Yet all over that country street signs and business billboards are appearing in English, beneath the Amharic. English is cool. The very lettering confers status.