I believe there are three types of sign language.
One, as we see waves his hands around in the air.
The second, uses just one hand and finger positions shows what he is saying.
Indian sign language. Not used but it was communication between ancient tribes. I’ve read that it is actually easier to learn than the other two types.
“The second, uses just one hand and finger positions shows what he is saying.”
Cued speech is fairly easy to learn. Very simplified explanation: When lip reading, Bat and Pat look alike. So do sip and zip. Cued speech uses one hand near the mouth to indicate the differences.
Per wikipedia, “Cued speech is a visual system of communication used with and among deaf or hard-of-hearing people. It is a phonemic-based system which makes traditionally spoken languages accessible by using a small number of handshapes, known as cues (representing consonants), in different locations near the mouth (representing vowels) to convey spoken language in a visual format.”