Early operators and late topic-drop/pro-drop

This paper compares two reduction principles in child language, Tense/Agreement Omission (Schütze 1997;Wexler 1998) and Root Peripheral Truncation (Rizzi 1994, 2001). The paper argues that the empirical content of these proposals as well as their partial overlap follows from an inherent hierarchy of acquisition steps of the kind predicted in Jakobson (1942). The empirical support for this reinterpretation follows from the construction of longitudinal graphs. The approach accommodates the lack of optional infinitives in Romance languages.