The main purpose of tongues and languages is the communication between people. Today it is much faster to send messages to any place in the world, but for quite some time people lived in isolation in their own groups. There were no means of communication or transport to facilitate communication.
Thus, each group of persons developed their own form and manner to communicate, by naming the world surrounding them, telling stories and conveying knowledge. This is the origin of languages and that’s why there are so many in the world – today there are more than 7 thousand tongues according to the Encyclopedia of Linguistics Ethnologue.
Language is a cultural trace, and as cultures vary, it is hard to imagine that all people in all places of the world could speak the same language. Besides, a language reflects the persons’ experiences and lives – even if all the planet’s inhabitants would adopt one single language, each region would use certain words more than others and some of them would be forgotten.
We can observe that, even in case of one single language, different regions use it in different forms – in Portuguese, for instance, the same root (manioc) may be called “macaxeira”, “aipim”, “mandioca”; and that without mentioning the words phonetics and some sentence structures that vary a lot in the same language. This is another evidence that a language is closely related to the culture and day-to-day of its speakers, what makes impossible the existence of a universal language to the entire planet.