Why are there language differences between Japan and other countries (the U.S.)?
Like any other language in the world, language was not invented by someone at a certain time. It is true that language was somehow created over a very long period of time.
For example, suppose that a long time ago, people lived together in a certain place. There was a kind of signal among the people who lived there that was understood only by the people there. It was a signal that was understood only by themselves, and those who came from elsewhere had no idea what it was. Over time, these cues gradually became words.
Thus, there are many languages that can be understood only in the local region in various parts of the world.
Japanese may be understood in Japan, but it is no longer understood in Korea, the country immediately next door. Even in Korea, the language spoken is completely different from that of China, the country next door.
In this way, different places have different languages. The United States and Japan are far apart. It is only natural that they speak completely different languages.
