The unification of morphology and syntax that we adopt in this book leads us to the conclusion that the morphological structure of the verb within which the inflection is inserted reproduces the syntactic structure of the sentence hosting the subject; thus the inflection has exactly the same status within the verbal constituent as a clitic subject within the sentence. This proposal is supported by several sets of data presented in section 2. The model we propose requires a different theory of agreement and chains, also discussed in section 3.