Although English is only one of the six official languages of the United Nations, it has become the "lingua franca" of international business and academia. When I used to work in countries around the world, everyone knew at least "Microsoft English" because they all used Windows.
When we add up the number of people who speak a language as their first or second language, English is the most prevalent language in the world today. By some estimates, 900 million people speak English as a second language.
Good explanation of how English changes here:
https://langster.org/en/blog/a-brief-history-of-the-english-language-from-old-english-to-modern-days