Sign languages


  • There is one sign language spoken all over the world.

    There are many sign languages all over the world, quite different from one another. The relationship of sign to meaning may not be quite as arbitrary as it is for spoken language, but there is still great room for variation.

  • American sign language (ASL) is just a system for spelling out English

    ASL is its own language with its own syntax and lexicon, exhibiting features that bear no typological relationship to English.

  • Sign languages are not as complex as spoken languages,

    Sign languages have the full range of expression of spoken languages, as evidenced by a full range of language artifacts like stories and poems. They have phonologies, morphologies, including grammatically obligatory information (inflection), and syntactic complexity, including embedded clauses and subordination,

    Phonologies? See below.


Stokoe (1960). Sign Language Structure Silver Spring Maryland: Linstok Press.

  1. What are phones? Meaningless, but repeatable subparts of meaningful units: morphemes.
  2. Can signs be broken down into meaningless subparts? Yes.
  3. Stokoe identified 3 components of signs in ASL
    1. hand shape
    2. location
    3. movement
    For example, the hand shape associated with CANDY (pointing finger) is not meaningful in itself.
  4. Change any of these 3 and you change the meaning of the word.

    The signs CANDY and APPLE have the same location and movement, and are distinguished only by their handshape (p. 345, Fig. 10.1) [p. 68 transparency slides]

    What shall we call such a pair of words?
  5. Call the handshape of CANDY extended index finger and the handshape of APPLE extended knuckle. extended index finger and extended knuckle are linguistic units which can function to make meaningful contrasts but which are themselves meaningless.
  6. Are extended index finger and extended knuckle allophones of one phoneme or are they separate phonemes?
  7. Similar pairs of words exist distinguished only by locations and movements.

Why are there phones? Why doesn't one word of English have clicks and another have ejectives and a third have high back unrounded vowels?

It would be a lot to remember: ease of encoding.

Probably even more important: ease of decoding. Acoustic signals are complex.

    Some pitch tracks and spectrograms

There are a lot of meanings out there. And a lot of noise in the world of signals.

With no phones, the problem of distinguishing among 1000 morphemes would be the problem of remembering and distinguishing 1000 discrete distinctions among continuously varying signals like that spectrogram.

With phones, we reduce the problem to making 30 or 60 distinctions reliably within that continuous stream of signals, still hard, as the difficulty of building speech recognition systems has shown us, but way easier.

Moral: The problem of meaning recognition needs to be broken up into parts: distinguish among a small set of signals and associate sequences of those signals with meanings.

This is called duality of patterning. There are two systems of patterns: phones and morphemes. The phone system has fewer contrasts. By weaving together sequences of phones we are able to make many more distinctions in the system of morphemes.

Something similar goes on when we move from morphemes to sentences. By weaving together sequences of morphemes we are able to make many more distinctions among meanings than we make with the morphemes alone.

Another way of putting it: Duality of patterning is what allows linguistic systems to be as complex as they are.


Stokoe's work changed the way people looked at ASL.

Previously people thought a sign was something completely different from a word in spoken language.

After Stokoe's work (further pursued in collaboration with Casterline and Croneberg), it became clear that sign languages had duality of patterning as well:

In fact, all sign languages did. In fact all sign systems had meaningless repeatable subcomponents. Call these formational elements:

    phone:morpheme :: formational element: sign

Why? For the same reason spoken languages do, probably. Having a continuous stream of 1000 signs with no formational elements would be as difficult to decode as a language without phones.

However there are some interesting lessons as well.

Notice that the formational elements of a sign do not have to be sequenced the way phones are. The handshape and motion can be simultaneous.

One of the interesting features of signing is that the medium allows independent elements to be simultaneous. And the system of formational elements exploits this.

The English spelling signs (one sign per letter of the English alphabet) are an entirely sequenced system. Native signers can spell out quite quickly and often do so for a variety of reasons (when speaking to beginning signers, for example), but they find extended spelling much less natural and efficient than signing.

However there are numerous sequenced features of signs as well. Action verbs that entail a spatial end point are characterized by a "hold" manner of movement at the end of the sign. Those with no spatial endpoint are executed with continuous movement at the end (Suppalla and Newport 1978)


What would be an example a formational element that can make a meaningful difference in language, but can also be simultaneous with other formational elements?



A quote:

    Thirty years ago when William Stokoe first published the first piece on ASL structure, the task he set for himself was to take sign-sized units and analyze them for their component phonological aspects (Stokoe 1960, Stokoe et al. 1965)> At that ime he concluded that there were three phonological components: the shape of the hand(s) when articulating a sign, which he called DEZ's, the location(s) on the body where the sign is articulated, which he called TABS; and the movement(s) of the hands in the course of changing locations or handshapes, which he referred to as SIGS. Stokoe purposely avoided terms that already had a use in linguistics, choosing CHEREME (from Greek xeir 'hand') as the superordinate term for these phonological components of signs, even though they were equivalent to phonemes in the American structuralist sense (as in e.g. Hockett 1958).

    Diane Brentari
    Language 68.2. 1992, pp. 359-374
    Review of Phonological Representation of the Sign: Linearity and non-Linearity in American Sign Language
    Wendy Sandler. Dordrecht: Foris 1989.

Some fairly random citations:

  1. Bellugi, U. and Klima, E. S. (1976). Two faces of Sign: Iconic and abstract. In S. Harnad, D. Horst & J. Lancaster (Eds.). Origins and evolution of language and speech. New York: Annals of the New York Academy of Sciences.
  2. Brentari, D. 1999. A prosodic model of sign language phonology. Cambridge MA: MIT Press.
  3. Corina, D. & W. Sandler. (1993). On the nature of phonological structure in sign language. Phonology 10. 165-208.
  4. Wilson, M. & Emmorey, K. (1997a). Working memory for sign language: A window into the architecture of the working memory system. Journal of Deaf Studies and Deaf Education, 2 (3), 121-130.
  5. Friedman, L. (1976). Phonology of a soundless language: phonological structure of ASL. Doctoral dissertation, University of California, Berkeley.
  6. Battison, R. (1978). Lexical borrowing in American Sign Language. Silver Spring, MD: Linstok Press.
  7. Mandel, M.A. 1977.Iconicity of signs and their learnability by non-signers. In W.C. Stokoe (Ed.) Proceedings of the First National Symposium on Sign Language Research and Teaching (pp. 259-266), Chicago, Illinois.
  8. Perlmutter, (1992). Sonority and syllable structure in American Sign Language. Linguistic Inquiry, 23 (3), 407-442.
  9. Supalla, T. (1982). Structure and acquisition of verbs of motion and location in American Sign Language. Doctoral dissertation, University of California, San Diego.
  10. Supalla, T. & E. Newport (1978). How many seats in a chair? The derivation of nouns and verbs in American Sign Language. In: P. Siple (ed.) Understanding language through sign language research. New York: Academic Press. 91-132.
  11. Hamburg workshop papers

Constraint on hand shape: A morpheme may contain either the finger group or the finger group index-plus-middle-finger but never both.

The sequence: all-five-fingers + index-plus-middle-finger is forbidden.


Spoken language: Assimilation is one sound changing one of its features to be more like another sound nearby.

[ih    n   ]  + [  k  r eh d ax b ax l] =  [ih ng     k   r eh d ax b ax l]
    ALVEOLAR  +  VELAR                  =     VELAR VELAR
n assimilates to ng because the ng is pronounced in the same place (velar) as the following k sound.

ASL example (Fog. 10.2 p. 347). Assimilation ASL Browser [Communication Technology Lab: Michigan State University]

  1. SLEEP: The 5 handshape is facing the face and is then pulled down and closes to represent the eyes closing. The head pulls down to further emphasize that a person is sleeping.
  2. SUNRISE: The C handshape represents the shape of the sun and the horizontal arm represents the earth's horizon. The movement of the hand shows the sun rising above the horizon. Movement parallel to body.
  3. OVERSLEEP: The two previous signs combined. SLEEP and SUNRISE. The motion of the hand toward the face and the motion of the head toward the hand is eliminated or greatly curtailed.
SLEEP         +   SUNRISE            =            OVERSLEEP
5 handshape      C handshape              5 handshape       C-handshape
closed              up                     closed              up
toward face  +  parallel to body       parallel to face + parallel to face
toward face and parallel to face are like phonological features like place of articulation. Note that motion of head also assimilates. SLEEP involves motion downward of head, but SUNRISE does not. Head motion eleiminated of greatly curtailed in OVERSLEEP.

What is prosody in speech? Perceived features:

  • rhythm
  • prominence
  • intonation

Sound stream features realizing prosody (what a phonetician would measure)

  • Rise and fall of pitch
  • Rise and fall of volume
  • Pauses, increases and decreases of speech rate, timing of emphasis

Sign language features for realizing prosody:

  • body posture
  • facial expression
  • Pauses, increases and decreases of speech rate, timing of emphasis

Example from Israeli Sign Language (ISL), F10.3, p. 348

    Yes/no question and shared information utterance have different facial expressions
The key point is that this facial expression for questions is grammaticalized (obligatory). It's not a question without it.

Productive processes for forming new words. Knowing the meaning of the first sentences, we can deduce a lot about the meaning of the second:

  1. scaff: The purpose of this machine is to scaff computers against viruses.
  2. The company purchased several expensive scaffers last year.
This is derivational morphology.

There is also inflectional morphology, the -s ending on walks, the -ed ending on walked. And Swahili agreement:

a -ta -ku -penda
he(SUBJ)- -(FUTURE) -him(OBJ) -like
He will like you.
u -ta -m -penda
you(SUBJ)- -(FUTURE) -him(OBJ) -like
You will like him.

Note that Swahili verbs agree with BOTH subject and OBJECT!

Will sign language have anything like this?


  • I show you
  • You show me
  • I show all of you Notice the handshapes are constant. The motion changes and because of that the starting point and ending point of the sign on the body change. But the basic planbe of the motion stays constant. Chest, shoulder height. 'I show you' and 'you show me' are almost exact inverses. Notice the movement is always FROM subject TO obvject. This a sequential feature of the sign show SAubnject agreement is shown at the beginning of the sign, object agreement at the end.
  • In some verbs the movements are in the opposite direction: INVITE, TAKE, COPY, ADOPT. (ISL and ASL agree on this list)
  • Not all verbs agree.

The phenomenon: hand shapes that stand for classes of things combine with different types and manners of movement. Reminiscent of classifiers in Navaho and Asian languages.

Specific hand shapes classify objects, then combine with a special class of other words to describe the motion or the location of those objects:

Classes: Predicates
Spatial position
  1. Cylindrical shaped object
  2. flat object
  3. small round object
  4. person
  1. straight
  2. pivot
  3. wander
  4. roll
  5. be next to


  1. 'A cup is next to a piece of paper'
  2. 'Two cars pass each other'

The term iconic is used for signs that have some salient feature that resembles what they signify.

Onomatopoeia is a special case of iconicity. Onomatopoietic words are words that describe sounds or things that have a salient and sound something like what they are describing.

By and large Onomatopoeia is the main way in which spoken language signs can be iconic.

But sign languages have the added possibility of visual iconocity and this introduces some interesting possibilities:

    washing machine twisting action represents twisting
    action of washing machine
    lump The forefinger indicates a bump (lump)
    on the back of the hand.
    sleeveless One hand indicates that the sleeves of a shirt are cut
    off at the top of the shoulder which means that there is no sleeve.

On the other hand, sometimes the iconicity is more elusive, and often not present at all.

    wind B handshapes circle each other
    represent something being wrapped
    wine W- handshape circles on cheek
    Lutheran The thumb of the L handshape is
    tapped against the open palm of the other hand.

An interesting mix of iconicity and other features is in language about motion:

    Data from ASL Browser
    English Japanese ASL
    walk aruku 3-handshapes represent the feet
    The action of hands represents
    a person walking
    wander   The upright index finger represents a person.
    The wavy movement of the finger represents aimless
    burabura aruku
    tobotobo aruku The movement of the fists represents the slow walk of
    an animal that is just trudging (plodding) along.
    Handshape changes from 3-handshape to fists, but
    greatly resembles the walking sign
    totter stumble yochiyochi aruku The V handshape represents a person.
    The action of the hand and the movement of
    the shoulders represent someone stumbling.
    waddle yoroyoro aruku
    lumber doshindodoshindo aruku
    limp  ?? aruku The sign WALK made with a jerky movement