ABSTRACT
English and Spanish differ with respect to the realization of grammatical subjects. Subjects are required in English; Spanish is a 'pro-drop language' in which the expression of subjects is mainly constrained by discourse-pragmatic factors. In this data, almost all adult statements with a verb in English occur with an overt subject. Adult statements in Spanish, by contrast, provide frequent subjectless models to the child, as in the interaction between Nico (N) and the author (C). The phenomenon is not optional in every possible environment, where a null subject is unacceptable in the conjoined sentence because it is the focus of a contrast with the subject of the preceding verb. For comparison reasons, therefore, here the chapter focusses on pronominal subjects only. In earlier work, it has shown that the siblings' use of subjects in English does not differ from what is typical for monolinguals.
