In two earlier posts, I discussed the idea of magic, my term for the deductive necessity that some linguistic property distinguishes those morphemes which undergo or do not undergo surface-unpredictable alternations. For instance, the Spanish verb negar ‘to deny’ diphthongizes under stress (e.g., niego ‘I deny’), whereas the superficially similar pegar ‘to stick to s.t.’ does not (pego ‘I stick to s.t.’), and there must be something different about the two stems that causes this.

In a forthcoming handbook chapter, Baković, E., Heinz, J., and Rawski (in press; henceforth BHR) take up the familiar Kiparskian question of the locuses of phonological abstractness, and in doing so, they discuss several ways in which this magic might be encoded. I would like to briefly review their taxonomy.

Under the suppletive analysis, magic verbs like negar have two stems underlying, perhaps /neg-/ and /njɛg-/, the latter used when primary stress falls on the stem. Linguists have—rightly, I think—been uncomfortable with this kind of analysis when the supposedly suppletive stem allomorphs are phonologically similar, and when the distribution of the allomorphs are easily stated in phonological or morphosyntactic terms; both are the case here. However, Aronoff (1994) argues that one must recognize the existence of suppletive patterns and his major case studies (from Hebrew and Latin) involve less-similar stem allomorphs whose distributions are not so easily stated.  I am not immediately convinced by Aronoff’s arguments, but I think they should be taken seriously. BHR are similarly skeptical of the use of suppletion except in cases where the allomorphs share little material (e.g., the Korean nominative, which is realized as /-ka/ or /-i/ depending on context).²

Under the abstract diacritic analysis, magical stems bear an feature which is part of the environment for some rule. One concrete version of this is to make the diacritic literally a rule feature, such that rule R cannot apply to a stem unless that stem bears the feature [+R]. For instance, we might represent the stems of the two Spanish verbs as /neg- {+diph}/ and /peg- {−diph}/.¹ We of course need then to write the diphthongization structural change (but this is not hard) and to specify its environment (but this no more or less hard than it would be under the suppletive analysis).

Finally, under the abstract phoneme analysis, magical stems contain phonemes³ which are “abstract” (in a sense to be specified shortly) and trigger the relevant rule (here, diphthongization). BHR discern two types of abstract phonemes: absolutely abstract phonemes are feature bundles which do not appear on the surface, and restrictedly abstract phonemes consist of surface-licit feature bundles which surface in the some, but not all, of the contexts in which they are posited.⁴

The distinction between abstract diacritics and abstract phonemes seems important. It is probably not surprising that self-described morphologists seem to prefer abstract diacritics whereas phonologists prefer abstract phonemes.

Endnotes

1. One can further imagine that {−diph} is not present underlyingly but is filled in by a lexical redundancy rule early in the derivation, at least for 1st (-a-) and 2nd (-e-) conjugation verbs for which non-diphthongization seems to be the default (see Gorman & Yang 2019 and citations therein). Similar redundancy rules will be called for all rules of “pure phonology”, those which do not show morpholexical conditioning.
2. This type of analysis is closely related to Gouskova and Pater’s concept of “exceptional morphs” in Optimality Theory.
3. I note it is not exactly the phoneme itself which is abstract, but rather the overall phonemic form of the morph. For instance, according to Lieber (1987:100f.), German umlaut (a fronting of a [+back] stem vowel) is triggered by a “floating” [−back] feature which is underlyingly present in just those stems which undergo umlaut.
4. It is not clear to me whether BHR treat this distinction as an object of grammar, or whether it’s just a descriptive notion.

References

Aronoff, M. 1994. Morphology by Itself. MIT Press.
Baković, E., Heinz, J., and Rawski, J. In press. Phonological abstractness in the mental lexicon. In The Oxford Handbook of the Mental Lexicon, to appear.
Gorman, K. and Yang, C. 2019. When nobody wins. In Franz Rainer, Francesco Gardani, Hans Christian Luschützky and Wolfgang U. Dressler (ed.), Competition in inflection and word formation, pages 169-193. Springer.
Harris, J. 1969. Spanish Phonology. MIT Press.
Harris, J. 1985. Spanish diphthongisation and stress: a paradox resolved. Phonology Yearbook 2:31-45.
Lieber, R. 1987. An Integrated Theory of Autosegmental Processes. State University of New York Press.