Morphology is the field of
linguistics that studies the internal structure of words. (Words as units in the
lexicon are the subject matter of
lexicology.) While words are generally accepted as being (with
clitics) the smallest units of
syntax, it is clear that in most (if not all) languages, words can be related to other words by rules. For example,
English speakers recognize that the words
dog,
dogs, and
dog-catcher are closely related. English speakers recognize these relations from their tacit knowledge of the rules of word-formation in English. They infer intuitively that
dog is to
dogs as
cat is to
cats; similarly,
dog is to
dog-catcher as
dish is to
dishwasher. The rules understood by the speaker reflect specific patterns (or regularities) in the way words are formed from smaller units and how those smaller units interact in speech. In this way, morphology is the branch of linguistics that studies patterns of word-formation within and across languages, and attempts to formulate rules that model the knowledge of the speakers of those languages.
The history of morphological analysis dates back to the ancient Indian linguist Pa?ini, who formulated the 3,959 rules of Sanskrit morphology in the text A??adhyayi by using a Constituency Grammar. The Graeco-Roman grammatical tradition also engaged in morphological analysis.
The term morphology was coined by August Schleicher in 1859[1]
The distinction between these two senses of "word" is arguably the most important one in morphology. The first sense of "word," the one in which dog and dogs are "the same word," is called lexeme. The second sense is called word-form. We thus say that dog and dogs are different forms of the same lexeme. Dog and dog-catcher, on the other hand, are different lexemes; for example, they refer to two different kinds of entities. The form of a word that is chosen conventionally to represent the canonical form of a word is called a lemma, or citation form.
