Peters' note is valuable as an overview of current knowledge about filler
syllables, in part because it clarifies how much we do NOT know about these
elements. The note also points to the potential value of filler syllables for
theoretical accounts of early language development, including contrasting
predictions derived from nativist accounts against those that Peters describes
as ‘constructivist.’ Characterizing the nature and function of filler elements
could be very helpful for distinguishing these accounts, particularly if the
focus is on identifying changes that might reflect a transition from phonological to morphological functions. As Peters indicates, differentiating these
functions is unlikely to be easy. Indeed, it will be particularly difficult if
Peters is correct in believing that the morphological categories are constructed; that position predicts a gradual transition from phonological to
morphological functions and thus a period during which filler syllables are
neither phonological nor morphological but, instead, somewhere in between.