Surface patterns or syntactic structure?

In Ancient Greek, the default case for subjects in infinitival phrases is the accusative. In this paper I give a diachronic explanation in terms of reanalysis and, more importantly, pattern extension. It is argued that the development is a-structural in that a surface pattern is extended irrespective of structural licensing. In the second part of the paper the default character of the accusative in infinitivals which is the result of pattern extension is accounted for on the synchronic level in a lexical inheritance network.