This paper analyses the acquisition of the functional categories
Agreement (AGR-S) and Tense (TNS) by monolingual English and
Catalan speaking children. The theoretical framework assumed is the
Principles and Parameters model of Generative Theory. The results of
the study show that all the children go through two stages in the acquisition
of these two functional categories: A first prefunctional stage,
characterised by the absence of syntactic projections for Agreement
and Tense; and a second, functional stage, in which children start to
show knowledge of the mechanisms and properties associated with the
two functional categories at stake. The results of this study provide evidence
for the Maturation of Functional Categories Hypothesis, as proposed
by Guilfoyle and Noonan (1988), Radford (1990), and Tsimpli
(1992), among others.
