2. WHAT IS SIGN LANGUAGE ? SIGN LANGUAGE IS A LANGUAGE THAT USES THE CONVENTIONAL SYSTEM OF MANUAL, FACIAL, AND OTHER BODY MOVEMENTS AS THE MEANS OF COMMUNICATION. SIGN LANGUAGE IS USED FOR FACILITATING COMMUNICATION AMONG DEAF PEOPLE OR SEVERELY DYSFUNCTIONAL NON-VERBAL PEOPLE IN THE WORLD.
4. A FORMAL CRITERION FOR A TRUE LANGUAGE MOST OF US HAVE HAD THE OPPORTUNITY TO EXPERIENCE SIGN LANGUAGE, IF ONLY TO SEE IT OCCASIONALLY IN THE CORNER OF OUR TV SCREENS. THERE WE CAN SEE A PERSON TRANLATING SPEECH INTO SIGN FOR THE BENEFIT OF DEAF AND SEVERELY HEARING –IMPAIRED VIEWERS. YOU MAY WONDER, AND QUITE JUSTIFIABLY, WHETHER THOSE SIGN TRULLY ARE PART OF A LANGUAGE OR ARE JUST A COLLECTION OF GESTURES THAT LACK THE SOPHISTICATION OF LANGUAGE BASED ON SPEECH.FROM THIS WE WOULD DETERMINE THAT A SIGN LANGUAGE IS A TRUE LANGUAGE BECAUSE THE LANGUAGE SYSTEM ALLOWS A SIGNER TO COMPREHEND AND PRODUCE AN UNRESTRICTED NUMBER OF GRAMMATICAL SIGN SENTENCES. THIS FEAT CAN BE ACCOMPLISHED WITH A LIMITED NUMBER OF SIGN ( VOCABULARY) AND A SYSTEM (SYNTAX AND SEMANTICS)
5. AN INFORMAL CRITERION FOR A TRUE LANGUAGE LANGUAGE MUST DEPEND ON SOME PHYSICAL MODE FOR ITS ACQUISITION AND USE BUT THAT MODE NEED NOT BE LIMITED TO SOUND. THE MODE CAN BE VISUAL, AS IN SIGNING, OR EVEN TOUCH AS IN LANGUAGE USED BY THE DEAF –BLIND
6. COMPLETE AND INCOMPLETE SIGN LANGUAGES Research on sign language seriously began for the most part in the 1960 s when linguist and psycholinguists addressed themselves to this newly discovered area. The findings showed that signers of such sign language as American Sign Language, French Sign Language, British Sign Language, and others can indeed communicate in sign whatever is expressed in speech(Stokoe, Casterline, & Cronoberg, 1965 ; Klima & Bellugi , 1979 ; and, more recently, Siple & Fischer, 1990 ). A sentence like that shown at the end of the previous section can be expressed through all of these languages.
7. SPEEDS OF SIGNING AND SPEAKING The speed at which signers produce sentences ( more precisely the ideas which underline sentences) in a signed conversation tends to be the same as that at which speakers produce sentences in a spoken conversation ( Bellugi & Fischer, 1972). This occurs even thought a signer, as does a speaker, has the ability to exceed this speed. There seems to be an optimum speed at which humans are comfortable in processing language information, whether that information be in the form of speech or sign.
8. GESTURES AND LANGUAGE BEFORE CONSIDERING THE ESSENTIALS OF SIGN LANGUAGE, IT WILL BE USEFUL TO EXAMINE THE RELATIONSHIP BETWEEN LANGUAGE AND GESTURES. GESTURES ARE VERY DIFFERENT WITH A LANGUAGE. GESTURES ARE ONLY THE COLLECTIONS OF SIGNS WHICH ARE LIMITED IN SCOPE AND DO NOT FORM A LANGUAGE
11. SPEECH-BASED SIGN LANGUAGES SIGN LANGUAGES USE THE PARTS OF HUMAN BODY IN THREE DIMENSIONAL SPACE AS THE PHYSICAL MEANS OF COMMUNICATION. SPEECH-BASED SIGN LANGUAGE REPRESENT SPOKEN WORDS AND THE ORDER OF THE WORDS OR MORPHEME AS THEY APPEAR IN ORDINARY SPOKEN LANGUAGE.
13. FINGER SPELLING THE SYSTEM WORDS WHICH ARE REPRESENTED BY SPELLING THEM OUT LETTER BY LETTER IN TERMS OF INDIVIDUAL SIGNS CAN BE CALLED BY FINGER SPELLING. IN THIS SYSTEM, HAND AND FINGER CONFIGURATIONS ARE USED TO INDICATE THE LETTERS. FINGER SPELLING CAN HELP THE DEAF PEOPLE TO UNDERSTAND THE IMPORTANT POINT OF LANGUAGE.