* Sign language variation: Sign languages are not just "translations" of spoken languages. They develop independently within communities, and even within a single country, there can be regional variations.
* Recognition: Not all countries formally recognize and codify their sign language. This can make it difficult to count them.
* Limited data: Research into sign language use and variation is ongoing, and the data isn't always comprehensive.
However, we can make some estimations:
* It's generally accepted that most countries have at least one sign language, with some having multiple.
* The World Federation of the Deaf estimates that there are over 300 sign languages globally, but this number is likely an underestimate.
* It's also important to note that sign languages are living languages and continue to evolve.
Therefore, while we can't give a definitive number, it's safe to say that the number of countries with their own sign languages is well over 100 and likely closer to the number of countries in the world.