Linguists have been attempting to define the range of locations in which infixes
can occur since Ultan's pioneering work in 1975, but to date there
has been no unambiguous evidence for infixation after the first syllable,
despite previous (now controversial) claims of its existence by Ultan (1975) and
Moravcsik (2000), as well as its predicted existence by Yu's Salient
Pivot Hypothesis (‘phonological pivots must be salient at the
psycholinguistic or phonetic level’) (2003, 2007). Previously
examined potential examples are controversial due to restricted patterns and the
acceptability of alternative analyses such as a first-vowel pivot or a
foot-based pivot (Samuels 2010). In this article, I present strong evidence from
fieldwork on Yeri, an endangered Torricelli language of Papua New Guinea, that
imperfective and additive morphemes productively occur as infixes after the
first syllable of the verb stem, and that a first-vowel or foot-based analysis
cannot account for their position.