INFIXES REALLY ARE (UNDERLYINGLY) PREFIXES/SUFFIXES: EVIDENCE FROM ALLOMORPHY ON THE FINE TIMING OF INFIXATION

Infixation and allomorphy have long been investigated as independent phenomena—see, for example, Ultan 1975, Moravcsik 1977, and Yu 2007 on infixation, and Carstairs 1987, Paster 2006, Veselinova 2006, and Bobaljik 2012 on allomorphy. But relatively little is known about what happens when infixation and allomorphy coincide. This article presents the results of the first crosslinguistic study of allomorphy involving infixation, considering fifty-one case studies from forty-two languages (fifteen language families). Allomorphy and infixation interact systemati-cally, with distinct sets of behaviors characterizing suppletive and nonsuppletive allomorphy involving an infix. Perhaps most notably, suppletive allomorphy is conditioned only at/from the stem edge, while nonsuppletive allomorphy is conditioned only in the surface (infixed) environ-ment. The robustness of these and related findings supports a universal serial architecture of the morphosyntax-phonology interface where: (i) infixation is indirect, involving displacement from a stem-edge position to a stem-internal one, counter to several influential theories of infixation (see especially McCarthy & Prince 1993a and Yu 2007); (ii) suppletive exponent choice is prior to (i.e. not regulated by) the phonological grammar (in line with Paster 2006, Pak 2016, Kalin 2020, Rolle 2021, and Stanton 2023, inter alia); and (iii) realization—including exponent choice and in-fixation—proceeds from the bottom of the morphosyntactic structure upward (à la Bobaljik 2000, Embick 2010, Myler 2017).