If everyone spoke the same language, communication would become less diverse and it would become impossible to explore one another's viewpoints. If everyone were to speak the same language, the world would be exactly the same if everyone were not speak at all.
With each separate language, dialect, and region comes a variety of cultural facets and attitudes that are able to expand the knowledge of every individual. While such barriers can be seen as obstacles, I would argue that the differences between each language tempts humans to explore more in order to understand one another better. With every variation in language not only do we, as people, discover more, but we also begin to understand more about the world around us.
In Russian there is a word called Тоска. It is impossible to translate the literal meaning of the word into English, however, it can be paraphrased to mean "yearning" or "melancholy". Yet, no single word in the English language can carry the magnitude of Тоска. It speaks of a type of pain that affects the soul, or the spirit, of a person. It is a type of anguish that seems like it will last forever, it is a type of longing that causes permanent restlessness in the brain. However, if the whole world were to speak only English, there is no possibility that this word could have been created. Without it, one would never be able to understand such a specific, yet important, emotion. While the word may be untranslatable, without it in the Russian language, such a concept would not exist. It would become impossible to sympathize with a person in such pain because it would become impossible to understand. It would become infinitely more difficult to learn more or expand one's knowledge because cultures and each variation in each language would be unable to contribute to the public's knowledge as a whole.
While it may seem that one universal language may only increase clarity in communication, it decreases our understanding of others and world around us, as it disallows for the possibility for multiple viewpoints to be established, developed, or contribute to the world as a whole.
However, if everyone were unable to speak, it would have the same effects as if everyone spoke the same language.
People would still be able to write, but more than likely poor and hard to understand writing would lead to greater misunderstanding. The small nuances that come with communicating with someone face-to-face or even simply through one's voice would be lost. Tone of voice, an important indicator in the meaning of one's words, would be lost. Certain cultural phenomenons, such as sarcasm, would cease to exist in the writing of the public eye. If no one was able to speak, the thirst for discovery and the varied viewpoints that contribute to knowledge as a whole would disappear; much like if everyone were to speak the same language.
