I have often wondered whether detailed representational formalism is somehow in conflict with genuine explanation in linguistics. I have been tangentially involved in the cottage industry that is applying the Tolerance Principle (Yang 2005, 2016) to linguistic phenomena, most notably morphological defectivity. In our paper on the subject (Gorman & Yang 2019), we are admittedly somewhat nonchalant about the representations in question, a nonchalance which is, frankly, characteristic of this microgenre.

In my opinion, however, our treatment of Polish defectivity is representationally elegant. (See here for a summary of the data.) In this language, fused case/number suffixes show suppletion based on the gender—in the masculine, animacy—of the stem, and there is lexically conditioned suppletion between -a and -u, the two allomorphs of the gen.sg. for masculine inanimate nouns. To derive defectivity, all we need to show is that Tolerance predicts that, in the masculine inanimate, there is no default suffix to realize the gen.sg. If there are two realization rules in competition, we can implement this by making both of them lexically conditioned, and leaving nouns which are defective in the gen.sg. off both lexical “lists”. We can even imagine, in theories with late insertion, that the grammatical crash is the result of uninterpretable gen.sg. features which are, in defective nouns, still present at LF.¹

It is useful to contrast this with our less-elegatn treatment of Spanish defectivity in the same paper. (See here for a summary of the data.) There we assume that there is some kind of grammatical competition for verbal stems between the rules that might be summarized as “diphthongize a stem vowel when stresssed” and “do not change”. We group the two types of diphthongization (o to ue [we] and e to ie [je]) as a single change, even though it is not trivial to make these into a single change.² This much at least has a venerable precedent, but what does it mean to treat diphthongization as a rule in the first place? The same tradition tends to treat the propensity to diphthongize as a phonological (i.e., perhaps via underspecification or prespecification, à la Harris 1985) or morphophonological property of the stem (a lexical diacritic à la Harris 1969, or competition between pseudo-suppletive stems à la Bermúdez-Otero 2013), and the phonological contents of a stem is presumably stored in the lexicon, and not generated by any sort of rule.³ Rather, our Tolerance analysis seems to imply we have thrown in our lots with Albright and colleagues (Albright et al. 2001, Albright 2003) and Bybee & Pardo (1981), who analyze diphthongization as a purely phonological rule depending solely on the surface shape of the stem. This is despite the fact that we are bitterly critical of these authors for other reasons⁴ and I would have preferred—aesthetically at least—to adopt an analysis where diphthongization is a latent property of particular stems.

At this point, I could say, perhaps, that the data—combined with our theoretical conception of the stem inventory portion of the lexicon as a non-generative system—is trying to tell me something about Spanish diphthongization, namely that Albright, Bybee, and colleagues are onto something, representationally speaking. But, compared with our analysis of Polish, it is not clear how these surface-oriented theories of diphthongization might generate grammatical crash. Abstracting from the details, Albright (2003) imagines that there are a series of competing rules for diphthongization, whose “strength” derives from the number of exemplars they cover. In his theory, the “best” rule can fail to apply if its strength is too low, but he does not propose any particular threshold and as we show in our paper, his notion of strength is poorly correlated with the actual gaps. Is it possible our analysis is onto something if Albright, Bybee, and colleagues are wrong about the representational basis for Spanish diphthongization?

Endnotes

1. This case may still be a problem for Optimality Theory-style approaches to morphology, since Gen must produce some surface form.
2. I don’t have the citation in front of me right now, but I believe J. Harris originally proposed that the two forms of diphthongization can be united insofar as both of them can be modeled as insertion of e triggering glide formation of the preceding mid vowel.
3. For the same reason, I don’t understand what morpheme structure constraints are supposed to do exactly. Imagine, fancifully, that you had a mini-stroke and the lesion it caused damaged your grammar’s morpheme structure rule #3. How would anyone know? Presumably, you don’t have any lexical entries which violate MSC #3, and adults generally does not make up new lexical entries for the heck of it.
4. These have to do with what we perceive as the poor quality of their experimental evidence, to be fair, not their analyses.

References

Albright, A., Andrade, A., and Hayes, B. 2001. Segmental environments of Spanish diphthongization. UCLA Working Papers in Linguistics 7: 117-151.
Albright, A. 2003. A quantitative study of Spanish paradigm gaps. In Proceedings of the 22th West Coast Conference on Formal Linguistics, pages 1-14.
Bermúdez-Otero, R. The Spanish lexicon stores stems with theme vowels, not roots with inflectional class features. Probus 25: 3-103.
Bybee, J. L. and Pardo, E. 1981. On lexical and morphological conditioning of alternations: a nonce-prob e experiment with Spanish verbs. Linguistics 19: 937-968.
Gorman,. K. and Yang, C. 2019. When nobody wins. In F. Rainer, F. Gardani, H. C. Luschützky and W. U. Dressler (ed.), Competition in Inflection and Word Formation, pages 169-193. Springer.
Harris, J. W. 1969. Spanish Phonology. MIT Press.
Harris, J. W. 1985. Spanish diphthongisation and stress: a paradox resolved. Phonology 2: 31-45.