What is the form of sign language that uses only one hand?

As a tactile signer, I'm in the habit of not only using ASL one-handed expressively, but also receptively. Switching arms every 20 ... Almost all sign languages around the world are signed with two hands in their "full" form, but there are many people who sign these languages with only one hand. read more

That said, Deaf people and users of sign language often use one hand to sign. This is usually done when the other hand is occupied, such as if you're on the phone or eating or writing (you can see an example here). read more

Similarly, countries which use a single spoken language throughout may have two or more sign languages, or an area that contains more than one spoken language might use only one sign language. South Africa, which has 11 official spoken languages and a similar number of other widely used spoken languages, is a good example of this. read more

Linguistically, signs that call for the active use of the non-dominant hand (ie, not"supportive" use), are almost always symmetrical. Think of PLAY, SWIM, DRAMA, and BATH - the hands have the same motion, handshape, and location. These signs are very easily understood when made with only one hand. read more

Similarly, the sign languages of Spain and Mexico are very different, despite Spanish being the national language in each country, and the sign language used in Bolivia is based on ASL rather than any sign language that is used in a Spanish-speaking country. read more