Morphophonemic changes

Editor's Notes

1. Sandhi is the process whereby the form of a word changes as a result of its position in an utterance (e.g. the change from a to an before a vowel).
2. The term "consonant gradation" refers to a word-medial alternation of consonants between fortis and lenis realizations. The fortis strong grade appears in historically open syllables (ending in a vowel), while the lenis weak grade appears in historically closed syllables (ending in a consonant). Fortis (of a consonant, in particular a voiceless consonant) strongly articulated, especially more so than another consonant articulated in the same place. Lenis (of a consonant, especially a voiced consonant) weakly articulated, especially denoting the less or least strongly articulated of two or more similar consonants. Vowel harmony is the phenomenon in some languages, e.g., Turkish, in which all the vowels in a word are members of the same subclass, for example all front vowels or all back vowels. Ablaut refers to a change of vowel in related words or forms, e.g., in Germanic strong verbs (e.g., in sing, sang, sung ).
3. Until the 1950s, many phonologists assumed that neutralizing rules generally applied before allophonic rules. Thus, phonological analysis was split into two parts: a morphophonological part, where neutralizing rules were developed to derive phonemes from morphophonemes; and a purely phonological part, where phones were derived from the phonemes. Since the 1960s (in particular with the work of the generative school, such as Chomsky and Halle's The Sound Pattern of English) many linguists have moved away from making such a split, instead regarding the surface phones as being derived from the underlying morphophonemes (which may be referred to using various terminology) through a single system of (morpho)phonological rules. The purpose of both phonemic and morphophonemic analysis is to produce simpler underlying descriptions for what appear on the surface to be complicated patterns. In purely phonemic analysis the data is just a set of words in a language, while for the purposes of morphophonemic analysis the words must be considered in grammatical paradigms to take account of the underlying morphemes. It is postulated that morphemes are recorded in the speaker's "lexicon" in an invariant (morphophonemic) form, which, in a given environment, is converted by rules into a surface form. The analyst attempts to present as completely as possible a system of underlying units (morphophonemes) and a series of rules that act on them, so as to produce surface forms consistent with the linguistic data.
4. The isolation form of a morpheme is the form in which that morpheme appears in isolation (when not subject to the effects of any other morpheme). In the case of a bound morpheme, such as the English past tense ending "-ed", it will generally not be possible to identify an isolation form, since such a morpheme does not occur in isolation.   It is often reasonable to assume that the isolation form of a morpheme provides its underlying representation. For example, in some American English, plant is pronounced [plænt], while planting is [ˈplænɪŋ], where the morpheme "plant-" appears in the form [plæn]. Here the underlying form can be assumed to be //plænt//, corresponding to the isolation form, since rules can be set up to derive the reduced form [plæn] from this (while it would be difficult or impossible to set up rules that would derive the isolation form [plænt] from an underlying //plæn//). This is not always the case, however; sometimes the isolation form itself is subject to neutralization that does not apply to some other instances of the morpheme. For example, the French word petit ("small") is pronounced in isolation without the final [t] sound, although in certain derived forms (such as the feminine petite) the [t] is heard. If the isolation form were adopted as the underlying form, the information that there is a final "t" would be lost, and it would be hard to explain the appearance of the "t" in the inflected forms.
5. Therefore, there must be a morphophonemic rule which determines the allomorphs [il] and [ir] of the prefix /in-/.
6. To some extent English orthography reflects the etymology of its words, and as such it is partially morphophonemic. This explains not only cats /s/ and dogs /z/, but also science /saɪ/ vs. unconscious /ʃ/, prejudice /prɛ/ vs. prequel /priː/, chased /t/ vs. loaded /ɪd/, sign /saɪn/ signature /sɪɡn/, nation /neɪ/ vs. nationalism /næ/, and special /spɛ/ vs. species /spiː/, etc.
7. The given example involves active morphology (inflection), and morphophonemic spellings are common in this context in many languages. Another type of spelling that can be described as morphophonemic is the kind that reflects the etymology of words. Such spellings are particularly common in English; examples include science /saɪ/ vs. unconscious /ʃ/, prejudice /prɛ/ vs. prequel /priː/, sign /saɪn/ signature /sɪɡn/, nation /neɪ/ vs. nationalism /næ/, and special /spɛ/ vs. species /spiː/.