In very ancient times geographical separation by sea, mountains, distance, was quite a huge barrier, that only occasionally was surpassed, therefore several independent ways of speaking evolved, sometimes from a common root (common language); most interesting (for me) is the fact that not all languages have a common root. This asserts something about the capacities of the human brain, and its 'necessity' to develop a language. I mean that language is not something to be invented, but something 'innate', that in one form or another needs to be expressed.

Because nature endowed us with a lot of sounds and shapes, so we had to utilize them to the max in the field of communication, language being its tool as well as in other domains. Somehow humans are genetically programmed to seek diversity and have the natural tendency to make use of all the possible given variables. In earlier ages, when people were more in close contact with nature, they artfully designed the letters of their language imitating many times the shapes of what they see around them in nature. Have a look at the Chinese characters ,a relatively old primitive language and notice how intricate and detailed its writting system is developed using a large variety of shapes ,compare it with the hieroglyphs and you will notice a similarity in the abundant usage of shapes. Throughout ages and the development of writting systems the letters arouse and were reduced to an alphabetical phonetic system, compact in nature. Nowadays in highly developed IT society ,the need for precision, quick and to the point means of communication led us mostly to seek communicating globally using one language. It was the natural evolution of the human's quest for a tool of communication, that was influenced by natural geographical boundaries, by the relation between man and his surrounding and by their ever evolving ways of thinking and progressive life styles.

i dont know, it kinda sucks XD

Different people, different languages

I think we have so many languages because way back when we all lived together in little communities and each little community had its own language, because there was no point in being able to communicate with people in North America if you didn't even know they existed because you lived in Europe.