It may come as a surprise to many people in the U.S. and U.K. that speaking more than one language is the norm rather than the exception. In prehistoric times, most people belonged to small linguistic communities, and spoke several languages to trade with, and marry into, neighbouring communities. Still today, remaining populations of hunter-gatherers are almost all multilingual. Papua New Guinea, a country smaller than Spain, still counts some 850 languages, or about one language per 10,000 inhabitants. In countries such as India, Malaysia, and South Africa, most people are bilingual or better. Even in the world at large, polyglots outnumber monoglots. And with the advent of the Internet, contact with foreign languages has become increasingly frequent, even for the most linguistically isolated of monoglots.

Queen Elizabeth I of England could speak at least ten languages: English, French, Spanish, Italian, Flemish, Latin, Welsh, Cornish, Scottish, and Irish. According to the Venetian ambassador, she possessed these languages “so thoroughly that each appeared to be her native tongue”. No wonder she didn’t want to get married.

To speak a language competently implies knowledge of the culture associated with the language. Multilingualism is closely linked to multiculturalism, and, historically, both came under attack with the rise of the nation state. In the aftermath of the Brexit referendum, the British Prime Minister Theresa May stated: “If you believe you are a citizen of the world, you are a citizen of nowhere”—as though that were somehow bad or abnormal. Human beings are far older than any country. Still today, some people believe that teaching a child more than one language can impair the child’s linguistic and cognitive development. But what’s the evidence?

According to several studies, people who study a language do significantly better on standardized tests. Language management calls upon executive functions such as attention control, cognitive inhibition, and working memory; and there is mounting evidence that bi- and multi-lingual people are better at analysing their surroundings, multitasking, and problem solving. They also have a larger working memory, including for tasks that do not involve language. In terms of brain structure, they have more grey matter (and associated activity) in the dorsal anterior cingulate cortex, a locus for language control and broader executive function. Superior executive function is, in turn, a strong predictor of academic success.

According to one recent study, when faced with moral dilemmas, people who think through a problem in a foreign language make much more rational (or ‘utilitarian’) decisions, perhaps because certain words lose some of their emotional impact, or because the problem is seen from a different cultural perspective, or processed through different neural channels. So if you have a second language, you can use it, like a friend, to check yourself.

The cognitive benefits of bi- and multilingualism yield important health dividends. An examination of hospital records in Toronto uncovered that bilingual patients were diagnosed with dementia on average three to four years later than their monolingual counterparts, despite being of a similar educational and occupational status. A more recent study in Northern Italy looking at patients at the same stage of Alzheimer’s Disease revealed that the bilingual patients were on average five years older, and that they had stronger connections between the brain areas involved in executive function. Similarly, research into 600 stroke survivors in India found that the bilingual patients had a much better outcome: specifically, 40.5% of the bilingual patients had normal cognition compared to just 19.6% of the monolingual ones.

And then there are the economic benefits. A U.S. study found that high-level bilingualism is associated with extra earnings of about $3,000 a year, even after controlling for factors such as educational attainment and parental socio-economic status. According to The Economist, for an American graduate, a second language could be worth—on a conservative estimate—up to $128,000 over 40 years. Of course, the overall economic impact of multilingualism is much greater than the sum of the higher earnings of multilingual speakers. A report from the University of Geneva estimates that Switzerland’s multilingual heritage contributes about $50 billion a year to the Swiss economy, or as much as 10% of GDP. Conversely, research for the U.K. government cautions that a lack of language skills could be costing the British economy around $48 billion a year, or 3.5% of GDP, in lost output.

Being bilingual may have important cognitive and economic benefits, but it is often the personal, social, and cultural benefits that multilingual people are keen to emphasize. Many bilingual people feel that the way they are, and the way they see the world—and even the way they laugh and love—changes according to the language they are speaking. In the 1960s, Susan Ervin-Tripp asked Japanese-English bilingual women to finish sentences in each language, and found that the women came up with very different endings depending on whether they were speaking English or Japanese. For example, they completed “Real friends should…” with “…help each other” in Japanese, but “…be frank” in English. “What do you want to eat?” “Who’s your favourite poet?” Ask a question in one language, and you get one answer; ask the same question in another language, and you get another one. “To have another language” said Charlemagne, “is to have another soul.”

Translation dictionaries seem to assume that languages are made up of corresponding words, but even when that is more or less the case, the equivalencies have different connotations. Compared to “I like you” in English, “Je t’aime” in French is a far more serious proposition. Owing to a certain je ne sais quoi, some things are more readily expressed in one language than another. By code switching, multilingual speakers can increase their range of expression, and perhaps even their range of thought. “The limits of my language” said Ludwig Wittgenstein, “are the limits of my world.” Certain languages are better suited to certain purposes, for example, English is great for science and technology, French is better for cooking and seducing, and Latin is best for praying and formal rites of passage. Multilingual people are free to pick and choose, maybe along the lines of Charles V, Holy Roman Emperor: “I speak in Latin to God, Italian to Women, French to Men, and German to my Horse.” (He didn’t get on with the German lords, and preferred to live in Spain, where he happened to be the King.)

The more languages you learn, the easier it becomes to learn languages. But learning a language also strengthens your first language. For instance, one study found that Spanish immersion significantly improved children’s native English vocabulary. More broadly, learning a language casts light upon your first language and language in general, increasing your appreciation of language and ability to communicate. “You speak English beautifully,” wrote Robert Aickman in The Wine-Dark Sea, “which means you can’t be English.”

Just before writing this article, I asked my amazing Facebook and Twitter people the following question: “If you are bi- or multi-lingual, what do you most value about that fact?”

And here are some of their responses:

• The freedom to access different cultures plus the possibility to read many authors in original version!
• Being fluent in a couple of other languages has given me insight into other ways of seeing the world. That helps empathy, and openness.
• I appreciate the cognitive advantages being multilingual has offered. Also the connections with culture, history, and the knowledge acquired.
• Language is knowledge. Always useful to be a little less ignorant.
• It feels as if I can switch into two different modes and think from different perspectives.
• Being more tolerant—new language = new culture, new and different perspectives/access to more information.
• That I can talk wine with twice as many ppl.
• It gives me patience and understanding for those who want to articulate, but have difficulty conveying what they really mean.
• The fact that I can fully understand and communicate in another language (Afrikaans) makes me feel good.
• It gave me an understanding that ‘thoughts’ don’t come into my head in a language at all. Thoughts come as ‘ideas’. Only when I have to verbalize my ideas, I have to use a language.
• I’m bilingual in India. There’s nothing special about it here. Know a ton of people who are trilingual. In India, multilingualism starts becoming impressive if the language count’s above like five or something.
• Obviously, being able to speak about people in elevators without them knowing what’s said. 😉
• Having a variety of options when cussing.

Every language has its own rules and conventions, its own sounds and rhythms, its own beauty and poetry, its own outlook and philosophy.

Every language is another way of being human, another way of being alive.