“…In particular, the VP-internal hypothesis (Koopman & Sportiche 1991, among others) has led to the obliteration of the distinction between internal and external arguments: as the single arguments of unaccusative and unergative verbs are both generated within the VP domain, the structural representation of the distinction is given at the level of different functional (or semi-functional) heads to which each argument moves. These theoretical refinements appear to question the validity of those diagnostics, such as ne cliticization in Italian or impersonal passivization, which previously depended on the characterization of arguments as internal or external: indeed, it has been shown that these constructions can allow both unaccusative and unergative verbs (although not to the same extent), depending on semantic factors such as the mutual predictability between a verb and its argument (Levin & Rappaport Hovav 1995, Lonzi 1985 or volitional control (Zaenen 1993). …”