American Sign Language (ASL) has grammar just like any other sign language or spoken language. Sign languages are produced in the visual-gestural modality, as opposed to the vocal-auditory modality of spoken languages, which has a unique impact on their grammars . The study of ASL structure dates back to William Stokoe, Dorothy Casterline, and Carl Croneberg in the 1960s. Since then, linguists have been describing patterns in ASL responsible for creating meaning at all kinds of levels, from the word, to phrases and sentences and beyond. Not all of these linguists ascribe to the same theoretical framework, using various theories, models, and analyses. Some analyze the language from a generative linguistics perspective, while others from a cognitive linguistics perspective.
Morphology In ASL morphology, publications have historically categorized morphological processes under two umbrellas: derivational morphology and inflectional morphology.
Derivational morphology Derivational morphology is the process by which new units can be created in a language, and like any other language, this process has been observed in a variety of forms in ASL.
One form of derivational morphology occurs when a change in movement changes the sign's meaningoften between a noun and a verb. Many ASL nouns are derived from verbs. This may be done either by reduplicating the movement of the verb if the verb has a single movement, or by restraining (making smaller and faster) the movement of the verb if it already has repeated movement. For example, the noun CHAIR is derived from the verb SIT through reduplication.
Another way of deriving new words in ASL is via the process of compounding, which often differ in meaning from their constituent signs. For example, the signs FACE and STRONG compound to create a new sign FACE^STRONG, meaning 'to resemble'. Compounds undergo the phonetic process of "hold deletion", whereby the holds at the end of the first constituent and the beginning of the second are elided: +ASL compounding Individual signsCompound sign FACE STRONG FACE^STRONG MH HMH MMH
Some linguists have analyzed various compounds as a type of suffixation. Agent nouns may be derived from verbs by adding the sign, or suffix, AGENT and deleting the final hold of the verb, e.g. TEACH+AGENT becoming 'TEACHER'. Superlatives have also been analyzed as created by a formed by suffixation, e.g. SMART+MOST becoming 'SMARTEST'. For example, Ted Supalla's work on ASL verbs of motion analyzed these signs as consisting of many different affixes, articulated simultaneously according to complex grammatical constraints. This differs from the concatenative morphology of many spoken languages, which except for suprasegmental features, such as tone, are tightly constrained by the sequential nature of voice sounds.
Numeral incorporation is another derivational morphological process that has been studied in ASL. Certain types of signs, for example, those relating to time and age, may incorporate numbers by assimilating their handshape. For example, the word for 'week' has handshape /B/ with the weak hand and /1/ with the active hand; the active hand's handshape may be changed to the handshape of any number up to 9 to indicate that many weeks. Some linguists have analyzed this phenomenon as a type of affixation. Signs of age, for example, will begin with a touch at the chin. They argue that this touch functions as a prefix which completely assimilates with the handshape of the corresponding age number. For instance, the word for 'nine' is signed with an /F/ handshape produced ipsilaterally in front of the signer's shoulder. The chin-touch in 'nine years old' can be analyzed as an affix, which is then produced with this same /F/ handshape. For 'three years old', however, the prefix is made with a 3 handshape.
Inflectional Morphology Inflectional morphology adds units of language to other words. For example, this would be changing 'watch' to 'watches' or 'watching.' In ASL, the sign may remain unchanged as WATCH, or the meaning may change based on non-manual markers (NMM).
ASL morphology demonstrates reduplication and indexicality as well.
Derivation There are about 20 non-manual modifiers in ASL, which are either adjectival or adverbial. For example, the adverb 'th', realized as the tongue being placed between the teeth, means 'carelessly / lazily' when combined with a verb:
Numeral incorporation and classifiers Rather than relying on sequential affixes, ASL makes heavy use of simultaneous modification of signs. One example of this is found in the aspectual system (see below); another is numeral incorporation: There are several families of two-handed signs which require one of the hands to take the handshape of a numeral. Many of these deal with time. For example, drawing the dominant hand lengthwise across the palm and fingers of a flat B hand indicates a number of weeks; the dominant hand takes the form of a numeral from one to nine to specify how many weeks. There are analogous signs for 'weeks ago' and 'weeks from now', etc., though in practice several of these signs are only found with the lower numerals.
ASL also has a system of classifiers which may be incorporated into signs. A fist may represent an inactive object such as a rock (this is the default or neutral classifier), a horizontal ILY hand may represent an aircraft, a horizontal 3 hand (thumb pointing up and slightly forward) a motor vehicle, an upright G hand a person on foot, an upright V hand a pair of people on foot, and so on through higher numbers of people. These classifiers are moved through sign space to iconically represent the actions of their referents. For example, an ILY hand may 'lift off' or 'land on' a horizontal B hand to sign an aircraft taking off or landing; a 3 hand may be brought down on a B hand to sign parking a car; and a G hand may be brought toward a V hand to represent one person approaching two.
The frequency of classifier use depends greatly on genre, occurring at a rate of 17.7% in narratives but only 1.1% in casual speech and 0.9% in formal speech.
Frames
Frames are a morphological device that may be unique to sign languages (Liddell 2004). They are incomplete sets of the features which make up signs, and they combine with existing signs, absorbing features from them to form a derived sign. It is the frame which specifies the number and nature of segments in the resulting sign, while the basic signs it combines with lose all but one or two of their original features.
One, the WEEKLY frame, consists of a simple downward movement. It combines with the signs for the days of the week, which then lose their inherent movement. For example, 'Monday' consists of an M/O hand made with a circling movement. 'MondayWEEKLY' (that is, 'on Mondays') is therefore signed as an M/O hand that drops downward, but without the circling movement. A similar ALL DAY frame (a sideward pan) combines with times of the day, such as 'morning' and 'afternoon', which likewise keep their handshape and location but lose their original movement. Numeral incorporation (see above) also uses frames. However, in ASL frames are most productively utilized for verbal aspect.
Verbal aspect
While there is no grammatical tense in ASL, there are numerous verbal aspects. These are produced by modulating the verb: through reduplication, by placing the verb in an aspectual frame (see above), or with a combination of these means.
An example of an aspectual frame is the unrealized inceptive aspect ('just about to X'), illustrated here with the verb 'to tell'. 'To tell' is an indexical (directional) verb, where the index finger (a G hand) begins with a touch to the chin and then moves outward to point out the recipient of the telling. 'To be just about to tell' retains just the locus and the initial chin touch, which now becomes the final hold of the sign; all other features from the basic verb (in this case, the outward motion and pointing) are dropped and replaced by features from the frame (which are shared with the unrealized inceptive aspects of other verbs such as 'look at', 'wash the dishes', 'yell', 'flirt', etc.). These frame features are: eye gaze toward the locus (which is no longer pointed at with the hand), an open jaw, and a hand (or hands, in the case of two-hand verbs) in front of the trunk which moves in an arc to the onset location of the basic verb (in this case, touching the chin), while the trunk rotates and the signer inhales, catching her breath during the final hold. The handshape throughout the sign is whichever is required by the final hold, in this case a G hand.
The variety of aspects in ASL can be illustrated by the verb 'to be sick', which involves the middle finger of the Y/8 hand touching the forehead, and which can be modified by a large number of frames. Several of these involve reduplication, which may but need not be analyzed as part of the frame. (The appropriate non-manual features are not described here.) stative "to be sick" is made with simple iterated contact, typically with around four iterations. This is the basic, citation form of the verb. inchoative "to get sick, to take sick" is made with a single straight movement to contact and a hold of the finger on the forehead. predisposional "to be sickly, to be prone to get sick" is made with incomplete motion: three even circular cycles without contact. This aspect adds reduplication to verbs such as 'to look at' which do not already contain repetition. susceptative "to get sick easily" is made with a thrusting motion: The onset is held; then there is a brief, tense thrust that is checked before actual contact can be made. frequentative "to be often sick" is given a marcato articulation: a regular beat, with 4–6 iterations, and marked onsets and holds. susceptive and frequentative may be combined to mean "to get sick easily and often": four brief thrusts on a marked, steady beat, without contact with the forehead. protractive "to be continuously sick" is made with a long, tense hold and no movement at all. incessant "to get sick incessantly" has a reduplicated tremolo articulation: a dozen tiny, tense, uneven iterations, as rapid as possible and without contact. durative "to be sick for a long time" is made with a reduplicated elliptical motion: three slow, uneven cycles, with a heavy downward brush of the forehead and an arching return. iterative "to get sick over and over again" is made with three tense movements and slow returns to the onset position. intensive "to be very sick" is given a single tense articulation: a tense onset hold followed by a single very rapid motion to a long final hold. resultative "to become fully sick" (that is, a complete change of health) is made with an accelerando articulation: a single elongated tense movement which starts slowly and heavily, accelerating to a long final hold. approximative "to be sort of sick, to be a little sick" is made with a reduplicated lax articulation: a spatially extremely reduced, minimal movement, involving a dozen iterations without contact. semblitive "to appear to be sick" [no description] increasing "to get more and more sick" is made with the movements becoming more and more intense.
These modulations readily combine with each other to create yet finer distinctions. Not all verbs take all aspects, and the forms they do take will not necessarily be completely analogous to the verb illustrated here. Conversely, not all aspects are possible with this one verb.
Aspect is unusual in ASL in that transitive verbs derived for aspect lose their transitivity. That is, while you can sign 'dog chew bone' for the dog chewed on a bone, or 'she look-at me' for she looked at me, you cannot do the same in the durative to mean the dog gnawed on the bone or she stared at me. Instead, you must use other strategies, such as a topic construction (see below) to avoid having an object for the verb.