It makes sense to me that there should be less languages needed and used over time as technology continues to make the world a smaller place.
Then I wonder if we will have less countries over time, however I think this question is very different then how many languages we need. Because people need and want to communicate, however for political and economic reasons there is less motivation to have fewer countries in the world. Also I think the Netherlands is a good example of the future, where people may speak a native more obscure language (Dutch) and also speak English as their international language of choice. I have seen people from different countries that all have different native languages e.g. Spanish, Chinese, Russian, etc. all communicate just fine using English.
Mandarin is the most widely spoken language in the world, because China has1.4+ billion people.
Over a billion people speak Mandarin, yet only 1% of Chinese people speak English. The evil Communist government does not want the people of China to learn English, because then they would learn and revolt against Communism.
Spanish is the second most widely spoken language on earth.
Only 13% of the people in the world are fluent at 3 languages and the term for this is trilingual.
However if you can speak 5 or more languages fluently you are not only most likely a genius you are known as a Polyglot.
Only 1% of the world's population is fluent and can communicate in 5+ languages, I have only ever met one person who could do this and he was definitely a genius. He was a medical professor that made a lot of money investing in the stock market and he lived in Monaco. He was also famous for his medical inventions.
