Language disorders as a window on universal grammar: An abstract theory ofagreement for IF, DP, and V-PP

A new concept of Agreement (AGR) has been represented as a Formal Feature t hat can appear in a wide range of different configurations (Chomsky, 1998). A case study from language disorders supports and extends this abstract co ncept. The child shows no agreement in Inflectional Phrase me cart and Dete rminer Phrase them eyes. We then extend the notion of AGR to include verb-P repositional Phrase relations, where the child also systematically avoids c ertain prepositions (go beach). The analysis is supported by intuitional da ta from compounds (sweep with broom --> broom-swept). We also define a syst ematic notion of Possible deficit as a premature fixation of functional ite ms which normally require additional Phi-features. The notion of Maximizati on of Formal Features then emerges as a significant feature of learnability from both a normal and disordered perspective. (C) 2001 Academic Press