Here's why:
* Independent Development: Sign languages evolved independently in different parts of the world, much like spoken languages. This means they have distinct signs, grammar, and structures.
* Cultural Influence: Sign languages reflect the culture and history of the communities they originated from. This leads to variations in vocabulary, expressions, and even the way signs are made.
* Regional Differences: Even within a single country, sign language can have regional variations, similar to dialects in spoken languages.
Examples:
* American Sign Language (ASL) is distinct from British Sign Language (BSL).
* French Sign Language (LSF) is different from Spanish Sign Language (LSE).
* Even within the United States, there are variations in regional sign languages, such as Black American Sign Language (BASL).
However:
* There are some similarities between sign languages, especially in basic concepts and expressions.
* Some sign languages have borrowed signs or elements from each other over time.
It's important to remember that sign languages are full-fledged languages with their own complex systems, and they deserve respect and recognition. If you're interested in learning sign language, make sure to learn the specific language used in your region or country.