morpheme (n.)

The minimal DISTINCTIVE UNIT of GRAMMAR, and the central concern of MORPHOLOGY. Its original motivation was as an alternative to the notion of the WORD, which had proved to be difficult to work with in comparing LANGUAGES. Words, moreover, could be quite complex in STRUCTURE, and there was a need for a single concept to interrelate such notions as ROOT, PREFIX, COMPOUND, etc. The morpheme, accordingly, was seen primarily as the smallest functioning unit in the composition of words.

Morphemes are commonly classified into free forms (morphemes which can occur as separate words) and bound forms (morphemes which cannot so occur – mainly AFFIXES): thus unselfish consists of the three morphemes un, self and ish, of which self is a free form, un- and -ish bound forms. A word consisting of a single (free) morpheme is a monomorphemic word; its opposite is polymorphemic. A further distinction may be made between lexical and grammatical morphemes; the former are morphemes used for the construction of new words in a language, such as in COMPOUND words (e.g. blackbird), and affixes such as -ship, -ize; the latter are morphemes used to express grammatical relationships between a word and its CONTEXT, such as plurality or past TENSE (i.e. the INFLECTIONS on words). Grammatical morphemes which are separate words are called (inter alia) FUNCTION WORDS.

As with all EMIC notions, morphemes are abstract units, which are realized in speech by DISCRETE units, known as morphs. The relationship is generally referred to as one of EXPONENCE, or REALIZATION. Most morphemes are realized by single morphs, as in the example above. Some morphemes, however, are realized by more than one morph according to their position in a word or sentence, such alternative morphs being called allomorphs or morphemic alternants/variants. Thus the morpheme of plurality represented orthographically by the -s in e.g. cots, digs and forces has the allomorphs represented phonetically by {-s}, {-z} and {-iz} respectively (morphemes are usually symbolized using brace brackets). In this instance the allomorphs result from the phonetic influence of the sounds with which the singular forms of the words terminate, the process being referred to as one of ‘phonological conditioning’. The phenomenon of alternative morphemic realization is called allomorphy.

The study of the arrangement of morphemes in linear sequence, taking such factors into account, is morphotactics. The application of morphemic ideas to the analysis of languages was particularly extensive in the 1940s and 1950s in post-BLOOMFIELDIAN linguistics, when the approach came to be called morphemics, and several analytical difficulties emerged. The English plural morpheme illustrates some of these. When the plurality is simply added to the root, as in the above examples, the correspondence between morpheme and morph is straightforward. But in cases like mouse ~ mice and sheep ~ sheep it is more problematic. Several solutions have been proposed to handle such cases: in the case of sheep, for example, a zero morph of plurality may be recognized, to preserve the notion of ‘sheep+ plural’, this being symbolized as  . Other concepts which have proved to be of importance in ‘morphemic analysis’ include (a) the empty morph, set up to handle cases where a FORMAL feature in a word cannot be allocated to any morpheme, and (b) the portmanteau morph, set up to handle cases where a formal feature can be allocated to more than one morpheme. Submorpheme is a term sometimes used to refer to a part of a morpheme that has recurrent form and meaning, such as the sl- beginning of slimy, slug, etc.