Update: Part 2 here
Sign Language is the natural language of the Deaf. It is a visual language and those who use sign language are called signers. Signers use their hands, shoulders, arms, torso, neck and face to communicate. In spoken languages, the basic unit of sound utterance is called a phonemes. Similarly, the basic unit of sign language are also called phonemes even though they are not based on sound.
The Liddel and Johnson model Sign language has five parameters that describe phonemes:
- handshape - decribed by which fingers and/or thumb are selected and flexed
- palm orientation (or just "orientation")- described by where the palm is facing
- hand location (or just "location") - described by where one or both hands are with respect to the face, shoulders, arms, and torso
- movement - described by movement of fingers, thumb, hand and arms
- non-manual signals (NMS) - which includes facial expression and body posture
Initial inventory of Filipino Sign Language (FSL) observed over ninety handshapes, approximately twenty locations, and six orientations. Movement can be grouped generally into two categories: gross arm movement (tracking the path of the hand and arm) and internal movement (changes in hand shape).
Liddell and Johnson further grouped these into segments; a Movement segment (M) and a Hold segment (H). Movement segments are portions of the sign where the hands (and arms) are motion or the hand shape is in transition. Hold segments are portions of the sign where there is no motion or where hand shapes are in steady state. Signs are then composed of one or more segments. For example, HMH means there is a Hold segment followed by a Movement segment followed by a Hold segment.
Segments observed in FSL include H, M, MH, HMH, and MHMH.