In singular-plural-dual triples, personal pronouns show the patterns in (1)-(4), but not the ABA pattern in (5), as shown by Smith et al. (2019), on the basis of data from many dozens of languages from around the world.
(1) AAA, e.g. Mapudungun 2nd person eymi – eym-ün – eym-u
(2) ABB, e.g. Kayardild 3rd person niya – bi-lda – bi-rra
(3) ABC, e.g. Savosavo 2nd person no – me – pe
(4) AAB, e.g. Yagua 2nd person jiy – jiryéy – sááda
Smith et al. (2019) also find that in nominative-acc/erg-oblique triples, personal pronouns show the patterns in (6)-(9), but not the ABA pattern in (10).
(6) AAA, e.g. Lezgian 1SG zun – za – zaz
(7) ABB, e.g. Latin 1SG ego – me – mihi
(8) ABC, e.g. Khinalug 1SG zɨ – jä – asɨr
(9) AAB, e.g. Wardaman 3SG narnaj – narnaji – gunga
This looks like a significant new finding which should be explained. Suppletion is strongly related to absolute high frequency (as I noted in an earlier post discussing Moskal 2015), so one might take usage frequencies as a starting point for an explanation, but I can only think of a possible way of explaining the relative rarity of the ABC and AAB patterns. (By far the most frequent patterns are AAA and ABB.)
The dual is much less frequent than the plural (which is in turn less frequent than the singular), and the oblique case forms are much less frequent than the accusative/ergative (which is in turn less frequent than the nominative). Suppletion needs high frequency, which disfavours the ABC pattern. And when there is analogical reorganization, it is usually a rarer form that is eliminated and takes on the stem of a more frequent form (thus, English kneel/knelt is leveled to kneel/kneeled, not to knell/knelled, because the present-tense form is more frequent). Thus, ABC will be regularized to ABB in preference to BBC (=AAB).
However, I cannot think of a good explanation of why *ABA should be even rarer than AAB and ABC. Is the dual somehow semantically closer to the plural than to the singular? Is an oblique form semantically more similar to an accusative or ergative than the nominative? These don’t seem plausible suggestions.
Thus, it is very interesting to see that Smith, Moskal, Xu, Kang, and Bobaljik (= Smith et al.) give an explanation for the absence of *ABA that is based on “containment” plus priority insertion of more specific forms (as per the Elsewhere Principle), much as in Bobaljik’s (2012) explanation of the absence of *ABA in comparatives and superlatives (*good – bett-er – good-est). This is an intriguing suggestion, and in the absence of a better explanation, it seems that it should be adopted. (Unfortunately, I cannot see how this explanation can possibly work, as I will explain below).
Smith et al. (roughly) propose the following underlying featural structures:
[[[pronoun] PL] DUAL]
[[[pronoun] ACC/ERG] OBL]
The idea is that in patterns like Latin ego ‘I.NOM’, m-e ‘I-ACC‘, and m-ihi ‘I-OBL’, the exponent m- is specified as occurring in the context “__] ACC]”, while the exponent ego occurs in the elsewhere case. Since the accusative case is contained in the representation of the oblique, the oblique must also have the exponent m-. It could have a different exponent only if the language had a more highly specified vocabulary item (like Khinalug asɨr, which is specified as occurring in the context “__] ERG]OBL]).” Thus, the hypothesis about containment plus the Elsewhere logic would explain the absence of ABA patterns.
It seems to me that unfortunately, this explanation cannot work (not for case suppletion, not for number suppletion, and not for comparatuve suppletion either), because it makes four presuppositions that can hardly be right:
(1) Homonymy is not possible. If homonymy were possible, then an ABA pattern could be easily generated by having two homonymous exponents, one of which is the default exponent and one of which is highly specified (to occur only in oblique or dual contexts). Homonymy is generally possible in languages, so a theory that relies on its non-existence can hardly be correct.
(2) There are no doublets. The Elsewhere logic only works if the existence of a suitable form blocks the generation of an alternative form, e.g. if the existence of a form better blocks the generation of *good-er. Now this is generally the case with comparatives and superlatives, but there are also languages where a regular and a suppletive comparative exist side by side (e.g. French meilleur and plus bon ‘better’). The Elsewhere principle would predict that plus bon should be blocked by the more specific exponent meilleur.
(3) Synthetic and analytic formations are completely different. One might want to say (like Bobaljik 2012 does) that plus bon is not blocked because it is analytic. But synthetic and analytic patterns obey basically the same generalizations elsewhere in grammar, as is (ironically) often pointed out by linguists working in the framework of Distributed Morphology. In Turkish, for example, the “postposition” ile and the instrumental “case suffix” -le/-la work in much the same way, with only a slight phonological difference. There is no good reason for saying that plus in plus bon is not a prefix in French.
(4) The effects of UG are not probabilistic. If one thinks probabilistically (as Greenbergian typology has done since the 1960s), then there is something odd about the idea that UG effects must be completely categorical. It is a perfectly coherent view that UG is not an absolute limitation on what is possible in languages, but merely guides grammars in certain directions, as envisaged by Jackendoff (2002: Chapter 4; “a set of attractors toward which languages tend statistically”), and a priori this is of course much more likely. It so happens that current generative grammar is committed to a discrete view of UG, but this leads to all kinds of artifacts, e.g. the distracting emphasis on explaining away a few problematic cases. It also makes it impossible to distinguish between rare patterns and frequent patterns (as discussed above), and thus to see further patterns that may be relevant to understanding what is going on.
In the last paragraph of the paper, the authors address an issue that I had raised earlier with them: How do we know that speakers actually analyze these forms, rather than simply storing them all, so that they are all suppletive (i.e. that all patterns are basically ABC)? The honest answer is: We don’t know it, except that if speakers did not do what Smith et al. claim they do, we would have no explanation of the cross-linguistic patterns. Thus, what we have here is a strong UG claim that is exclusively based on typological patterns. (Moreover, for the claim that case features are arranged hierarchically so that the containment explanation can work, again the motivation seems to come exclusively from typological patterns.)
But of course, there are different kinds of explanations for typological patterns, as was emphasized repeatedly and prominently by Stephen R. Anderson (discussed on this blog here and here). And I think that it should be clear that non-UG-based explanations (of the functional or diachronic sort) should take precedence over UG-based explanations, which are inherently less likely.
In the case of the missing ABA patterns, I do not know of an alternative explanation, as I noted above. Thus, this could somehow be hard-wired into the language faculty. But how this could happen is a real puzzle, because logically possible patterns like English-prime “good – better – goodest” or Latin-prime “ego – me – egohi” are readily learnable. Learnability cannot be the issue, so what is the problem?
I am still looking for an explanation.
Bobaljik, Jonathan David. 2012. Universals in comparative morphology: Suppletion, superlatives, and the structure of words. Cambridge, MA: MIT Press.
Jackendoff, Ray. 2002. Foundations of language: Brain, meaning, grammar, evolution. Oxford: Oxford University Press.
Moskal, Beata. 2015. Limits on allomorphy: A case study in nominal suppletion. Linguistic Inquiry 46(2). 363–376. doi:10.1162/LING_a_00185.
Smith, Peter W., Beata Moskal, Ting Xu, Jungmin Kang & Jonathan David Bobaljik. 2019. Case and number suppletion in pronouns. Natural Language & Linguistic Theory. doi:10.1007/s11049-018-9425-0. http://lingbuzz.auf.net/lingbuzz/003110