ABSTRACT
Young children frequently omit the subject of their sentences. This general observation has been made for a number of languages, including English, Italian, and American Sign Language, among many others. If, as the learnability arguments would suggest, the initial settings on the null argument parameters do not allow null arguments, then the grammatical explanation for the early null subject phenomenon would seem to be disconfirmed. If the American children were leaving off subjects because they considered it a grammatical option, they would be expected to leave off subjects at a higher rate than they do, and they would be expected to produce fewer pronominal subjects than they do. The grammatical explanations that have been proposed thus far encounter difficulties when a wider range of data are brought to bear on the question of the missing subjects in young children's utterances.
