When we think of “language,” we may have an image of something that has a fixed form and is almost complete. In reality, however, the world of language is full of variation and change.
　On an individual level, we use different expressions depending on who we are talking to and the situation. Even a single speaker has a wide range of words at his or her disposal. There are also characteristics that can be seen in groups, such as regional and social groups. Individuals who use slightly different variants gradually come together, and groups come together to form a group that shares a single language.
　On the other hand, languages change from day to day. Some of these changes are internal, and occur as a result of the biological limitations of the speakers, making it easier to express oneself or easier to understand. There are also external changes, such as the addition of new names for things that speakers encounter, or the change in meaning of names for things that are no longer used, or even the disappearance of words themselves. In addition, knowledge and wisdom gained in everyday life may accumulate over time, as in the case of proverbs. The way we use language may also change in the direction of more pleasant communication in our interactions with other people. The different variants within each group, and the changes that occur in these variants, accumulate to form a language. The result of this accumulation over tens of thousands of years is the 7,000 or so languages that exist in the world today.
　Even when we look at languages as a whole, they are full of change. Sometimes languages disappear when there are no more speakers, and conversely, new languages are born. For a language to be handed down, there must be a community of speakers. If the language used by the whole community of speakers changes, as happened in some regions during the colonial era when the language of the ruling power became the main language, the original language may cease to be used. If you move to a new place and there is no community of speakers around you, your children will learn the language of the country and will not inherit your language. This is particularly important for sign languages, and since more than 95% of families with hearing impaired children speak spoken languages, schools for the deaf, where deaf children gather, have played an important role as places where sign languages are inherited.
　For every language, there are speakers who cherish the language and its history. There are people who can express themselves and live their lives to the fullest by using that language. The total population of the world is 7.75 billion. I hope that the world will become a society where everyone can express themselves freely and make the most of their abilities, no matter where they are or what language they use.