Parametric variation: The case of Brazilian Portuguese null subjects

This chapter revisits comparative and diachronic studies of linguists analysing
Brazilian Portuguese (BP) with regard to the NSP, especially in view of recent
debates on the existence of the so-called partial null subject languages. It will be
shown that BP is losing the properties of a prototypical NSL like European
Portuguese (EP), with a rich inflectional paradigm, but, as the change is very recent,
there is still not a consensus regarding the target of the change. Our question is
whether BP classifies as a PNS language like Finnish, Hebrew or Marathi, as was
recently claimed in Holmberg (2010), and Holmberg & Sheehan (2010).
Methodologically, it is our purpose to observe the overt and null subjects in real data so
as to check whether eventual optionality of null and overt pronouns can be
attributed to a grammatical competition from a diachronic perspective (Kroch 1994)
or to some licensing possibility within a single type of grammar, which is normally
a view taken by formal linguists analyzing synchronic data. Using acquisition data
we will show that while null non-referential subjects are part of Brazilian core
grammar, null referential subjects are not, and their existence in the production
of Brazilian literate adults results from instruction through schooling. The chapter
suggests that from a typological view BP is a semi-NS language like Icelandic.