Hiatus resolution in Turkish: An underspecification account

This article examines how heterosyllabic vowel sequences are formed within words in Turkish and provides a unified account for vowel hiatus resolution mechanisms in spoken informal registers. Vowel assimilation (VA) optionally applies to avoid heterosyllabic sequences by forming long vowels. It is shown that the Articulator features of vowel sequences must be shared, and only high vowels can assimilate to low ones, the sequence [e.i] constituting an exception. Assuming minimum lexical specification, the effects of VA are analyzed based on autosegmental phonology and underspecification with crucial reference to other phonological processes of Turkish such as vowel harmony. The restrictions on VA and the exceptionality of [e.i] are straightforwardly explained through the underspecification of vowels for [Coronal] and [High]. Since high vowels have no specification for tongue height (TH), low vowels cannot assimilate to high vowels. Likewise, since [e.i], which contains all coronal sounds, has no shared specified Articulator feature, [i] cannot assimilate to [e]. When VA is not applicable, glide epenthesis applies to avoid hiatus. It is argued that epenthetic sounds, glides and vowels alike, are the syllabically conditioned realizations of a sonorant underspecified for TH. The consequences of the underspecification account for palatalization and disharmony are discussed.