As mentioned in Section 4.2, treating verbal morphology as pronominal means that overt preverbal subjects (PSs) are not the ‘real’ subject of a clause in an NSL, but perhaps a dislocated or A′ constituent. Even if one does not accept the pronominal agreement hypothesis, the distribution of PSs seems to be substantially different from that of overt subjects in languages like English. For these reasons, much of the debate over the past 30 years has centered on the status of PSs (see Rizzi, 1982; Rigau, 1988; Contreras, 1991; Koopman and Sportiche, 1991; Solà, 1992; Zubizarreta, 1994; Cardinaletti, 1997, 2004; Alexiadou and Anagnostopoulou, 1998; Goodall, 1999; Ordóñez and Treviño, 1999; Suñer, 2003; Camacho, 2006; Frascarelli, 2007; Sheehan, 2007, among others). This debate usually conflates logically independent notions: first, whether PSs occupy an A or A′-position, second, whether PSs have the properties of clitic left-dislocated (CLLD) phrases, and third, whether they are interpreted as topics or not.
These notions overlap in many ways, but they are not completely identical. For example, some researchers argue that PSs are CLLD phrases based on similarities with respect to reconstruction and scope, following Cinque (1990, 66). Thus, according to Cinque, sentences like (1a) and (2a) differ with respect to the possibility of interpreting the first constituent in its base position: The former can be interpreted as its counterpart in (1b), without displacement, whereas the latter cannot.