Subject ellipsis in early child English

English-speaking children are known to omit subjects. Parametric analyses of the phenomenon have the advantage to give a simple answer to why children omit subjects and how they reach an adult grammar: the problem is reduced to a matter of parameter misseting and resetting. However, early parametric analyses of missing subjects were challenged by empirical findings. In this paper, I present a parametric analysis of null subjects in finite clauses. In this analysis, three parameters interact to explain the pattern of subject omission in adult and child language.