Nobody knows how many languages there are.
The experts know there are thousands.
The problem is: what is a "language"? What is a "dialect"?
There are 7,000,000,000 human beings.
One book says that most of those people speak one of about 30 languages.
Some books say these are the six most widely spoken languages: English, Mandarin Chinese, Hindi/Urdu, Spanish, Russian / Belarusian, and Arabic. (Other books may have a different list.)
Most people seem to feel that English is now the international language. It seems to be the language of the global economy; it seems to be the language of the World Wide Web.