When I was a child, my great-grandmother, whom we called Daa, came to live with my family in Umuahia in south-eastern Nigeria. My father had spent most of his infancy in her care, mostly during a period when his mother was preoccupied with her role as one of the founders of a local Assemblies of God church. As Daa grew older and weaker, he felt it was his turn to take care of her. After much persuasion, he finally convinced her to leave her humble dwellings in a village far from where we lived and come spend her last days in the comfort of our modern home.

Each time I watched her shuffle one foot in front of the other, her back bent almost double until her head nearly touched the top of her walking stick, it was hard to imagine my father’s descriptions of a Daa who was once one of the tallest and most stunning women around. The story went that the colonial-era arbitrator who presided over the dissolution of her first marriage found her so beautiful that he decided on the spot to take her as one of his wives. “How can you maltreat such a beautiful woman?” he was said to have asked the errant husband.

Daa’s favourite pastime turned out to be watching American wrestling matches on TV. She had lived almost an entire lifetime with no television; and yet no other entertainment that the channels had to offer caught her fancy. With her ashen legs stretched stiff in suspense, she stared agape, chuckled loudly and gasped audibly as Mighty Igor and his ilk beat each other up on the small screen. Daa also enjoyed telling stories. But, apart from popular words like “TV” and “rice”, she knew no English. Her one and only language was Igbo. This meant that her storytelling sessions often involved vivid gesticulations and multiple repetitions so that my siblings and I could understand what she was trying to say, or so we could say anything that she understood.

None of us children spoke Igbo, our local language. Unlike the majority of their contemporaries in our hometown, my parents had chosen to speak only English to their children. Guests in our home adjusted to the fact that we were an English-speaking household, with varying degrees of success. Our helps were also encouraged to speak English. Many arrived from their remote villages unable to utter a single word of the foreign tongue, but as the weeks rolled by, they soon began to string complete sentences together with less contortion of their faces. My parents also spoke to each other in English – never mind that they had grown up speaking Igbo with their families. On the rare occasion my father and mother spoke Igbo to each other, it was a clear sign that they were conducting a conversation in which the children were not supposed to participate.

Over the years, I endured people teasing my parents – usually behind their backs – for this decision, accusing them of desiring to turn their children into white people. I read how the notorious former Ugandan president Idi Amin, in the 70s, brazenly addressed the United Nations in his mother tongue. The Congolese despot Mobutu Sese Seko also showed allegiance to his local language by dumping his European names. More recently, the internationally acclaimed Kenyan writer Ngũgĩ wa Thiong’o, after a successful career writing in English, decided to switch almost entirely to writing in his native Gikuyu. Upholding one’s mother tongue over English appeared to be the ultimate demonstration of one’s love of people and country – a middle finger raised in the face of British colonialism.

Lee Kuan Yew, the first prime minister of Singapore, thought differently. When he replaced Chinese with English as the official medium of instruction in his country’s schools, activists accused him of trying to suppress culture. The media portrayed him as “the oppressor in a government of ‘pseudo foreigners who forget their ancestors’,” as he explained in his autobiography, From Third World to First. But he believed the future of his country’s children depended on their command of the language of the latest textbooks, which would undoubtedly be English.

“With English, no race would have an advantage,” he wrote. “English as our working language has … given us a competitive advantage because it is the international language of business and diplomacy, of science and technology. Without it, we would not have many of the world’s multinationals and over 200 of the world’s top banks in Singapore. Nor would our people have taken so readily to computers and the internet.” Within a few decades of independence from Britain in 1965, Singapore had risen from poverty and disorder to become an economic powerhouse. The country’s transformation under Lee’s guidance is often described as dramatic.

My parents shared Lee’s convictions. They hoped English would give their children an advantage. But, as potent as that reason might be, my father admitted to me that it was secondary. He had an even stronger motivation for preferring English: “We spoke it to set ourselves apart,” he said. “Those of us who were educated wanted to distinguish ourselves from those who had money but didn’t go to school.”

Adaobi Tricia Nwaubani with her father and brothers in Umuahia in the early 1980s. Photograph: Courtesy of Adaobi Tricia Nwaubani

A perennial issue among the Igbo of south-eastern Nigeria is the battle between the mind and the purse; between certificate and cash. All over Nigeria, the Igbo are recognised for their entrepreneurial spirit and business acumen. From pre-colonial times to today, a majority of the country’s successful traders and transporters have been Igbo. Many of them began as apprentices and worked their way up, never bothering with school. The Igbo are also known for ostentatiousness and flamboyance – those with great wealth usually find it difficult to be silent about it. While the moguls flaunted their cash, the educated members of my parents’ generation flaunted their degrees, many from British and American schools. They might not have had the excess cash to fling at the masses during public functions or to acquire fleets of cars, but they could speak fluent English – an asset that was not available for purchase in stores.

I still remember strangers staring and smiling at us in wonder whenever my family talked among ourselves in public. Speaking English was just one way of showing off, especially when one lived, like my parents, in what was then a small, little-known town. Some of my parents’ contemporaries distinguished themselves by appending their academic qualifications to their names. Apart from academics and medical doctors, it was common to hear people describe themselves as Architect Peter or Engineer Paul or Pharmacist Okoro.

My father’s first degree was in economics, while my mother’s was in sociology. They met during the civil war between the government of Nigeria and the secessionist Igbo state of Biafra, and they spoke to each other in English throughout their three years of courtship, long before any of their children were born. “That was one of the things that attracted your daddy to me,” my mother said. “The way I spoke English fluently.” Back then, villagers made fun of my father for his choice of wife. They sneered that his determination to marry a university graduate had blinded him to the choice of a woman who was so skinny that she could surely never carry children successfully in her womb. Even if female university graduates were scarce, couldn’t he marry an uneducated woman and then send her to school?

The simmering resentment between those with certificates and those with cash exploded to the surface in the 1990s, when the Nigerian economy plunged. Suddenly, it was not so difficult to find an educated wife willing to marry a man who could also take on the responsibility of her parents’ and siblings’ welfare. Whether or not he could speak English or read and write was immaterial. Around that same time, a significant number of uneducated but daring Igbo men found infamy and fortune by swindling westerners of millions through advance fee fraud, known locally as 419 scams. There were stories of learned men – professors and engineers and accountants – being openly scorned during community meetings. “Thank you for your speech, but how much money are you going to contribute?” they would be asked. “We are not here to eat English. Please, sit down and keep quiet.” There were also stories of 419 scammers sneering back at those who mocked their incorrect English and inability to pronounce the names of their luxury cars. “You knows the name, I owns the car,” they would say.

This longstanding battle between the mind and the wallet is probably why Igbo has suffered the most among Nigeria’s three main languages. The other two, Yoruba and Hausa, despite facing threats from English as well, seem not to be doing as badly. Yoruba is one of the languages on a list of suggestions for London police officers to learn, while the BBC World Service’s Hausa-language operation has a larger audience than any other. Meanwhile, Igbo is among the world’s endangered languages, and there is a rising cry, especially among Igbo intellectuals, for drastic action to preserve and promote our mother tongue.

Many of the children who admired people like my family grew up determined that their own children would also speak English. My parents spoke excellent English – my father certified as an accountant in Britain, while my mother acquired a PGCE in education and then taught in London primary schools. They quoted Shakespeare and used words like “effluvium” in everyday speech. Not many of the new generation of parents speaking English to their children have a command of the language themselves. Unfortunately, the public school system in Nigeria has continued to deteriorate, and few parents can afford the private education that could provide their children with good English lessons. There is now an alarming number of young Igbo people who are not fluent in their mother tongue or in English.

My difficulty in communicating with Daa was not the only disadvantage of not being able to speak Igbo as a child. Each time it was my turn to stand and read to my primary school class from our recommended Igbo textbook, the pupils burst into grand giggles at my use of the wrong tones on the wrong syllables. Again and again, the teachers made me repeat. Each time, the class’s laughter was louder. My off-key pronunciations tickled them no end.

But while the other pupils were busy giggling, I went on to get the highest scores in Igbo tests. Always. Because the tests were written, they did not require the ability to pronounce words accurately. The rest of the class were relaxed in their understanding of the language, and so treated it casually. I considered Igbo foreign to me, and approached the subject studiously. I read Igbo literature and watched Igbo programmes on TV. My favourite was a series of comedy sketches called Mmadu O Bu Ewu, which featured a live goat dressed in human clothing. After studying Igbo from primary school through to the conclusion of secondary school, I was confident enough in my knowledge to register the language as one of my university entrance exam subjects.

Everyone thought me insane. Taking a major local language exam as a prerequisite for university admission was not child’s play. I was treading where expert speakers themselves feared to tread. Only two students in my entire school had chosen to take Igbo in these exams. But my Igbo score turned out to be good enough, when combined with my scores in the other two subjects I chose, to land me a place to study psychology at Nigeria’s prestigious University of Ibadan.

Eager to show off my hard-earned skill, whenever I come across publishers of African publications – especially those who make a big deal about propagating “African culture” – I ask if I can write something for them in Igbo. They always say no. Despite all the “promoting our culture” fanfare, they understand that local language submissions could limit the reach of their publications.

Nwaubani’s parents as a young couple in Nigeria, circa 1970. Photograph: Courtesy of Adaobi Tricia Nwaubani

Indigenous works form an essential part of a people’s literary heritage, and there is definitely a place for them – but not, it seems, when it comes to world domination, or pushing beyond the boundaries of our nations and taking a place of influence on the world stage. Every single African writer who has gained some prominence on the global scene accomplished this on a platform provided by the west, to whom our local languages are of absolutely no significance.

Africans are no longer helplessly watching outsiders tell our own stories, as we did in past decades, but foreigners still retain the veto over the stories we tell. Publishers in Britain and America decide which of our narratives to present to the world. Then their judges decide which of us to award accolades – and subsequent fame. The literary audiences in our various countries usually watch and wait until the west crowns a new writer, then begin applauding that person. Local writers without some western seal of approval are automatically regarded by their compatriots as inferior.

The west is also where our books scoop the easiest sales. The west has better marketing and distribution structures, while those which exist in the majority of African countries are simply abysmal. Nigerians in Punxsutawney can have access to my novels if they so desire, and so can those in Pontypridd. But in my country, where online shopping is still an esoteric venture, my books are accessible to the public in only a handful of cities.

Over the past decade alone, a number of major literary prizes have been awarded to writers of African origin. Ngũgĩ has been rumoured as having been considered for the Nobel prize in literature. That would hardly have happened had he begun his career writing in Gikuyu. He would probably not even have been known beyond the peripheries of Kenya, where the prevalence of that local language begins and ends. As the Nigerian author Chinua Achebe noted in a 1964 essay: “Those of us who have inherited the English language may not be in a position to appreciate the value of the inheritance. Or we may go on resenting it because it came as part of a package deal which included many other items of doubtful value and the positive atrocity of racial arrogance and prejudice … But let us not in rejecting the evil throw out the good with it.”

Perhaps Ngũgĩ and some other African writers care little about westerners being able to read their works. It could be that Nobel prizes and sales figures mean absolutely nothing to them. Maybe they are quite content with a local audience – but the local audiences themselves may not be able to read the authors’ books written in Gikuyu or Igbo or Chi.

Africa currently has the world’s lowest literacy rates. Unesco reports that more than 1 in 3 adults in sub-Saharan Africa are unable to read and write, as are 47 million young people (ages 15-24). The region accounts for almost half of the 64 million primary school-aged children in the world who are not in school. Not even the English are born with the ability to read their language. They are taught – usually in schools.

I wonder how many literate Gikuyu speakers can read their language. I wonder how many have read Ngũgĩ’s work. My parents, who have spoken Igbo their entire lives, can hardly read and write their mother tongue fluently. They were never taught. At the time they went to school, the colonials, whom we detest so much, were probably still busy transcribing our own mother tongues for us – from ideograms to the more universal Roman letters – to enable us begin to read and write our own local languages.

Daa eventually got weary of modern life and sulked until my father allowed her to return to her village, where she eventually died peacefully in her sleep. But it was not until the 2000s that I finally understood her fascination with US wrestling, after a former colleague told me of how her aged grandmother, while visiting from her village and watching Jerry Springer for the first time, suddenly exclaimed in shock: “Ah! So white people fight?!”

All those years ago, Daa was probably equally intrigued to see white people punching each other on TV. Living in Umuahia, where the sight of a white person is still today so rare that it draws a crowd in the street, meant that the few Caucasians Daa had glimpsed in her lifetime were probably missionaries and colonial officers – most of whom were models of civilisation, poster boys of higher breeding. When she came to stay with my family, she must have been shocked by the uncharacteristic sight of white people acting so savagely on TV.

That said, having one language to dominate others must have reduced conflict. If, for example, we decided to dump English and use a mother tongue as the language of instruction in local schools, which of the at least 300 tongues in Nigeria or the 70 in Kenya or the 120 in Tanzania (and so on) would those countries use to teach their children? This would be more difficult than ever today, when many African societies are becoming urbanised, with different ethnic groups converging in the same locality. Which language should schools select and which should they abandon? How many fresh accusations of marginalisation would arise from this process?

Lee Kuan Yew pointed out in his book how a multitude of mother tongues could have been a major hindrance to Singapore’s national security. Without a unifying language, the country’s armed forces faced a huge risk: “We were saddled with a hideous collection of dialects and languages,” he wrote, “and faced the prospect of going into battle without understanding each other.”

In Africa’s case, it would not just have been going to battle without understanding each other, but going to battle because we do not understand each other. The many wars around Africa are usually fought along ethnic lines. The lack of a common language would have further accentuated our differences, giving opportunity for yet more conflict. Languages like English have made Africa a more peaceful and unified region than it might have been. The contemptible colonials at least gave us an easy means of communicating with one another, preventing a Tower of Babel situation on the continent.

I attended a school in Nigeria where speaking your mother tongue was banned for that very reason. Shortly after the Nigerian civil war, which was instigated by venomous tribal sentiments, my country’s government hatched the idea of special schools in every state. A quota system would ensure that as many ethnic groups as possible were represented in each of the “unity schools”. For the first time in Nigeria’s history, children from every region would have the opportunity to mix and to get to know one another beyond the fog of tribalism. We were taught to see ourselves as Nigerian, not Igbo or Hausa or Yoruba or whatever. Local languages were part of the curriculum, but speaking them beyond the classroom was a punishable offence.

It was not until university that I at last began to speak the language. In Ibadan, away from Igbo land and from the laughing voices, away from those who either did not allow me to speak Igbo or who did not believe I could speak it, I was finally free to open my mouth and express the words that had been bottled up inside my head for so many years – the words I had heard people in the market speak, the words I had read in books and heard on TV, the words my father had not permitted around the house.

Speaking Igbo in university was particularly essential if I was to socialise comfortably with the Igbo community there, as most of the “foreigners” in the Yoruba-dominated school considered it super-important to be seen talking our language in this strange land. “Suo n’asusu anyi! Speak in our language!” they often admonished when I launched a conversation with them in English. “Don’t you hear the Yorubas speaking their own language?”

Thus, in a strange land far away from home, I finally became fluent in a language I had hardly uttered all my life. Today, few people can tell from my pronunciations that I grew up not speaking Igbo. “Your wit is even sharper in Igbo than in English,” my mother insists. Strangely, whenever I am in the presence of anyone who knew me as a child, when I was not permitted to speak Igbo, my eloquence in the local tongue often regresses. I stammer, falter, repeat myself. Perhaps my tongue is tied by the recollection of their mockery.

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• This article was amended on 18 March 2019 to correctly render Lee Kuan Yew’s name on second mention as Lee, rather than Yew, as per the conventions of names of Chinese origin.