Most modern sign languages come genetically from British sign language or French Sign Language. https://www.reddit.com/r/language/comments/ewtpnj/sign_language

Most modern sign languages come genetically from British sign language or French Sign Language. https://www.reddit.com/r/language/comments/ewtpnj/sign_language_family_tree/ https://www.reddit.com/r/language/comments/ewtpnj/sign_langu...