Since Hauser-Chomsky-Fitch (2002) the operation Merge has been taken to be the discriminating boundary between language and non-language. In our project, we propose some reflections on the simplest stage of this syntactic mechanism, namely the so-called Head-head Merge (Primary Merge in Rizzi’s 2010 Complexity Scale), showing that silent functional categories must be necessarily assumed in order to explain the realization of the most basic hierarchical structure. In this perspective the notion of “protolanguage” turns out to be as contradictory as the notion of “protogrammar”. The rise and explosion of overt functional categories should be taken as an object of investigation proper of the field of Historical Grammar.
