1. Definition

According to recent syntactic theories, clauses are structured in three main layers, which are organized into sub-units. The lowest layer is primarily lexical and consists of the verb plus its arguments, and is referred to as the VP (Verb Phrase) domain. On top of the VP layer, there is the inflectional layer called the IP (Inflectional Phrase) domain, which is the domain for the realization of tense, nu…