The conversation between human and AI assistant.
How many and what languages should one learn in order to be able to speak to at least 90% of all humans?
Wow, that's interesting. But what if I just want to learn only one or two languages?
If you only want to learn one language, then Mandarin Chinese would be the best choice because it is spoken by the largest number of people in the world. If you want to learn two languages, then consider Mandarin and Spanish as they have the highest number of native speakers combined.