Published online by Cambridge University Press: 27 June 2016
In the literature on Null Subject Languages (NSLs) since Rizzi (1982), the three properties that are commonly thought to be connected are (i) the richness of inflectional morphology, (ii) free subject inversion, and (iii) the COMP-trace effect. The connection between them is that if a language (e.g., Italian) has the option of having a null subject (NS) pronominal pro in subject position (i.e., SpecIP) as a result of having rich inflectional (i.e., verbal agreement) morphology, as represented in (1a), then the same element may appear in the same position in cases of subjects occurring postverbally as in (1b) and in cases of long-distance subject extraction where the postverbal trace is properly governed by the verb, as in (1c):