We know of over 10 brand-new languages that are still being developed! And all of them are sign languages.
What is more unusual: many of the founders of these languages are still alive! Some of these sign languages are very small, some are larger. Often the
signing community consists of both deaf and hearing signers.
How is a new language created? New languages develop when there are no alternatives around to learn. This can happen when only very few people in a community are deaf, for example, and they have no one around to learn an old
sign language from.
People without language still want to talk and communicate. And indeed, we
see that once people find someone to talk to — even in small communities
of 10, 20 or 100 people—a language is likely to form.