[This is part of a series of defectivity case studies.]

The earliest discussion of defectivity within the generativist tradition can be found in an early paper by Halle (1973:7f.).

…one finds various kinds of defective paradigms in the inflection. For instance, in Russian there are about 100 verbs (all, incidentally, belonging to the so-called “second conjugation”) which lack first person singular forms of the nonpast tense. Russian grammar books frequently note that such forms as (8) “do not exist” or “are not used”, or “are avoided.”

(8)
*lažu ‘I climb’
*pobežu (or *pobeždu) ‘I conquer’
*deržu ‘I talk rudely’
*muču ‘I stir up’
*erunžu ‘I behave foolishly’

Subsequent work slightly lowers Halle’s estimate of 100 verbs. By combining evidence from Russian morphological dictionaries, Sims (2006) provides a list of 70 defective verbs, and Pertsova (2016) further refines Sims’ list to 63. But by any account, defectivity affects many more verb types than, for example, in the English verbs.

All of the defective verbs end in a dental consonant—s, z, t, or d—and belong to the second conjugation, in which verbs form infinitives in -et’ or -it’), and are defective only in the 1sg. non-past form, marked with a –u and a mutation of the stem-final dental.

Baerman (2008) provides a detailed history of the mutations of t and d. The modern mutations, to š and ž respectively, represent the expected Russian reflexes of Common Slavic *tʲ, *dʲ, respectively. Christianization, beginning at the close of the first millennium, brought about a period of substantial contact with southern Slavic speakers, and their liturgical language, Old Church Slavonic (OCS), contributed novel reflexes of *tʲ, *dʲ, namely č [tʃʲ] and žd [ʐd] . The OCS reflexes were found in, among other contexts, the 1sg. non-past—where they competed with the native mutations—and the past passive participle, where they were largely entrenched. Ultimately, č persisted in the 1sg. non-past but žd was driven out sometime in the early 20th century (ibid., 85). However, the latter persists in past passive participles (e.g., rodit’ ‘to give birth’ has the past passive participle roždënnyj).¹ The OCS affricate mutations are rarely found in contemporarily written Russian. However, Gorman & Yang (2019; henceforth G&K) cite some weak evidence that the OCS mutation has some synchronic purchase in the minds of Russian speakers. First, Sims (2006) administers a cloze task in which Russian speakers are asked to produce the 1sg. non-past of a defective verb shown in the infinitive (e.g., ubedit’ ‘to convince’) and several participants select the OCS-like ubeždu, which is proscribed. Secondly, Slioussar and Kholodilova (2013), Pertsova (2016), and Spektor (2021) catalog what happens when verbs borrowed from English end in a dental consonant. For instance, from the English friend comes zafrendit’ ‘to add s.o. to one’s friend list on social media and rasfrendit’ ‘to unfriend s.o. on social media’, and among the many options, they find instances of the OCS-like zafrenždu in addition to the expected zafrenžu. To add to the confusion, there there is some hesitation on the part of Russian speakers to apply either of the expected 1sg. non-past mutations, and some speakers produce the the unexpected, unmutated zafrendu.² There is no precedent for this among native Russian verb lexemes.

The mutations of s and z to š and ž, respectfully, have no competitor inherited from contact with OCS. These mutations occur across the board. However, that’s not quite the whole story: English borrowings in the Slioussar and Kholodilova corpus often fail to alternate. For instance, for fiksit’ ‘to fix s.t.’, they record both the expected fikšu as well as the unexpected, unmutated fiksu. 

G&K develop an account of the Russian verbal gaps which assume that each of these four dental consonants does have a synchronically active competitor, and that there is simply no default. They couch this in terms of the Yang’s Tolerance Principle, but even one rejecting that particular method of deciding what is and is not productive might still agree with the basic insight—as indicated by English dental-stem loanwords—that the dental mutations are no longer productive and that this lack of productivity, along with sparse data during acquisition, results in defectivity.

Other accounts of this phenomena can be found in ch. 7 of Sims 2015 and in Pertsova 2016. These two studies contain many interesting suggestions for future work. However, with respect I must say I am not sure how to operationalize their suggestions as part of a mechanistic account of these observations.

Postscript

The aforementioned defectivity is the subject of occasional humor among Russian speakers. For instance, as discussed by as discussed by Sims (2015:5), a Russian translation of one of Milne’s Winnie the Pooh stories has the anthropomorphic bear puzzling over the 1sg. of pobedit‘ ‘to be victorious’. This suggests that Russian verbal defectivity has risen to the level of consciousness, and may reflect sociolinguistic “change from above”.

Endnotes

1. This form was cited in G&K:186; I have taken the liberty of fixing an inconsistency in the transliteration: there рождённый was transliterated as roždënny (note the missing final glide).
2. Russian has many indeclinable nouns, nouns which do not bear the ordinary case-number suffixes (Wade 2020:§36-40). For instance, radio ‘ibid.’ and VIČ ‘HIV’ can be used in any of the six cases and two numbers, but never bears any case-number suffixes. Crucially, though, indeclinables, unlike the aforementioned verbs, are either phonotactically-odd loanwords or acronyms, but as far as I can tell there is nothing phonotactically odd about zafrendit’ or its stem. And one should certainly not equate indeclinability and defectivity.

References

Baerman, M. 2008. Historical observations on defectiveness: The first singular non-past. Russian Linguistics 32: 81-97.
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.
Halle, M. 1973. Prolegomena to a theory of word formation. Linguistic Inquiry 4: 3-16.
Pertsova. 2016. Transderivational relations and paradigm gaps in Russian verbs.
Glossa 1: 13.
Sims, A. 2006. Minding the gap: Inflectional defectiveness in a paradigmatic theory. Doctoral dissertation, Ohio State University.
Sims, A. 2015. Inflectional Defectiveness. Cambridge University Press.
Slioussar, N. and Kholodilova, M. 2011. Paradigm leveling in non-standard Russian. In
Proceedings of the 20th meeting of Formal Approaches to Slavic Linguistics, pages 243-258.
Spektor, Y. 2021. Detection and morphological analysis of novel Russian
loanwords. Master’s thesis, Graduate Center, City University of New York.
Wade, T. 2020. A Comprehensive Russian Grammar. Wiley Blackwell, 4th edition.