With great clarity Ann Peters has summarized the way we have been viewing ‘fillers’ from the time they were considered a nuisance for seriously studying the development of language; the different roles they fulfill, depending on the developmental stage; and important open questions that should bring our understanding of fillers ahead. She notes that the reason for having ignored fillers for quite a while is that ‘they do not fit neatly into linguist's notions about ‘modules’ of language because at the very least they straddle preconceived boundaries.’ In fact, it is not a coincidence that researchers began to develop an interest for such neglected entities, as the interfaces of grammar began to play a central role in our understanding of language architecture. Being at the crossroads of phonology, morphology and syntax, fillers resist a rigidly compartmentalized view of language.

Although interest in fillers has grown amazingly, we definitely need more detailed descriptions of filler production and development, in order to be able to distill individual and language specific trends. On this note, I want to emphasize some of the general features of early fillers and argue that they neither support nor justify the assumption of a pregrammatical stage. On the contrary, their very presence argues against it.