AcI and control infinitives: How different are they?: A diachronic approach

In German, there are two infinitive constructions for complement infinitives, the accusativus cum infinitivo (AcI) and the object control infinitive construction (OCIC). Both constructions have nearly identical structures, where the logical subject of the infinitive is a distinct constituent from the rest of the infinitival clause, although in Modern German they show differences in form: the AcI is coherent and governs the bare infinitive, while the OCIC is incoherent and governs the zu-infinitive. It can be shown that these differences only developed over time and are reflexes of semantic differences between the constructions rather than of structural differences. Superficial binding differences that suggest a structural difference follow instead from the structures of the involved verb phrases.