The paper investigates a number of asymmetries in the behavior of subjects in Germanic, Celtic/Arabic, Romance, and Greek. The languages under investigation divide into two main groups with respect to a cluster of properties, including the availability of pro-drop with referential subjects, the possibility of VSO/VOS orders, the A/A' status of subjects in SVO orders, the presence/absence of Definiteness Restriction (DR)-effects in unaccusative constructions, the existence of verb-raising independently of V-2, and others. We argue that the key factor in this split is a parametrization in the way the Extended Projection Principle (EPP) is checked: move/merge XP vs, move/merge X-O. The first option is taken in Germanic, the second in Celtic, Creek, and Romance. According to our proposal, the EPP relates to checking of a nominal feature of AGR (cf. Chomsky 1995), and move/merge X-O languages satisfy the EPP via V-raising, as their verbal agreement morphology includes the requisite nominal feature (cf. Taraldsen 1978). Moreover, we demonstrate that the further differences that exist between Celtic/Arabic on the one hand and Romance/Greek on the other are related to the parametric availability of Spec,TP for subjects (cf. Jonas and Bobaljik 1993, Bobaljik and Jonas 1996). In Celtic and Arabic, Spec,TP for subjects is licensed, resulting in VSO orders with VP external subjects. In Greek and Romance, Spec,TP is not licensed, resulting in 'subject inverted' orders with VP internal subjects. In other words, we show that within the class of move/merge X-O languages, a further partition emerges which is due to the same parameter dividing Germanic languages into two major classes. We demonstrate that combining the proposed EPP/AGR parameter with the Spec,TP parameter gives four language-types with distinct properties.
