The Chinese dialects combined already have more native speakers than any other language, followed by Hindi and Urdu, which have the same linguistic origins in northern India. English comes next with 527 million native speakers. Arabic is spoken by nearly 100 million more native speakers than Spanish, which has 389 million speakers.
Which languages will dominate the future? Predictions vary, depending on your location and purpose. But here are a few ways to approach this question.
You want to make money in growth markets? These will be your languages.
In a recent U.K.-focused report, the British Council, a think tank, identified more than 20 growth markets and their main languages. The report features languages spoken in the so-called BRIC countries — Brazil, Russia, India, China — that are usually perceived as the world's biggest emerging economies, as well as more niche growth markets that are included in lists produced by investment bank Goldman Sachs and services firm Ernst & Young.
"Spanish and Arabic score particularly highly on this indicator," the British Council report concluded for the U.K. However, when taking into account demographic trends until 2050 as laid out by the United Nations, the result is very different.
Hindi, Bengali, Urdu and Indonesian will dominate much of the business world by 2050, followed by Spanish, Portuguese, Arabic and Russian. If you want to get the most money out of your language course, studying one of the languages listed above is probably a safe bet.
Of course, demographic developments are hard to predict. Moreover, the British Council only included today's growth markets, which says little about the growth potential of other nations that are still fairly small today. Also, Arabic and Chinese, for instance, have many dialects and local versions, which could make it harder for foreigners to communicate.
Despite all that, the chart above gives a broad look into which linguistic direction the business world is developing: away from Europe and North America, and more toward Asia and the Middle East.
You want to speak to as many people as possible? How about Chinese, Spanish or French?
German linguistic expert Ulrich Ammon, who conducted a 15-year-long study, recently released a summary of his research. In his book, Ammon analyzes the languages with the most native speakers and the most language learners around the world. Especially for the latter aspect, there is little original data available, which is why Ammon does not provide predictions of exact numbers of speakers per language.
Here's his top three of the languages you should learn if you want to use the language as often as possible, everywhere in the world. If you do not have time, however, don't worry too much: English will continue to top all rankings in the near future, according to Ammon.
1. Chinese. "Although Chinese has three times more native speakers than English, it's still not as evenly spread over the world," Ammon said. "Moreover, Chinese is only rarely used in sciences and difficult to read and write."
2. Spanish. Spanish makes up for a lack of native speakers — compared with China — by being particularly popular as a second language, taught in schools around the world, Ammon said.
3. French. "French has lost grounds in some regions and especially in Europe in the last decades," Ammon explained. "French, however, could gain influence again if west Africa where it is frequently spoken were to become more politically stable and economically attractive."
A 2014 study by the investment bank Natixis even predicted that French would become the world's most widely spoken language by 2050. The authors of the study referred to were demographic growth prospects in Africa. "French is also widespread in many smaller countries," Ammon said. However, the study did not take into account a significant fact: Not everyone who lives in countries where French is spoken is actually fluent in French.
You want to visit as many countries as possible but speak just one language?
This map shows the number of countries where certain languages are spoken. Most of these languages also appear in the two categories above. But a word of caution: In many nations, a language might be spoken by some, but mastered by few.
What to learn if you're interested in culture
Although the graphics below might appear confusing at first, they enlighten an often neglected aspect when assessing the world's major languages.
A group of international researchers recently analyzed 2.2 million book translations from around the world: Their visualization, based on data provided by UNESCO’s Index Translationum project, offers rare insights into so-called hub languages, which are especially significant culturally: If a book is published in a smaller language, it will usually be translated into a hub language. In this graphic, hub languages are characterized by their central position, multi-connectedness and the intensity of the nations' relationship — which are visually emphasized by the width of the lines.
For instance, books from Azerbaijan (one of the green countries) will nearly always be translated into Russian.
From Russian, a book will most likely be translated into English — which is the world's premier hub language for written publications.
French, as well as other European languages, such as Italian, German or Dutch, are also particularly significant hub languages.
What is interesting about this graphic is that cultural significance does not appear to correlate with the most recent economic or demographic importance of a language: German, Dutch or even Russian are still disproportionately represented.
Shahar Ronen, who was among the researchers who produced the graphics, says that the latest data on languages used on Twitter shows a clear trend, though: Some more traditional languages, which are dominant hub languages for book translations, will lose influence. "As it often happens, the rise of some languages comes at the expense of others. Russian and German are two languages whose global impact is on the decline: both are top languages in book translations and Wikipedia, but barely make it to the top 15 on Twitter," Ronen explained.
In other words: There is no one single language of the future. Instead, language learners will increasingly have to ask themselves about their goals and own motivations before making a decision.