This paper considers and compares the status of the concept of head within different
grammatical frameworks (Minimalism, LFG and HPSG) and its relevance to
our understanding of the mechanisms of change involved in grammaticalization.
Our data is drawn from the developments of lexical prepositions into grammatical
prepositions and complementizers in Romance and Germanic. We argue in favour
of a non-derivational approach and in particular against accounts in which all developments
are mediated through a chain of functional heads of the kind deployed
in cartography and nanosyntax.