Historical comparative work must present major challenges with sign languages. (The Japanese paper drasvi linked to above gives an idea of this; it’s in English, BTW.) The criteria for cognacy, and what actually constitutes a plausible historical change in the case of signs, as opposed to ...
Learn how to communicate 150 common Auslan signs, like “please,”“thanks,” and “how are you?” Each sign is clearly presented, with a photo of the handshape used to form the sign and a video clip demonstrating how the sign is produced. ...