In this paper we will propose a syntactic analysis of the distribution of
auxiliaries in the first stages of acquisition of Italian. The lexical- syntactic
structure of verb classes is acquired early on (Lorusso et al. 2005,
Friedman 2007): children distinguish between unaccusatives and
transitives. The first auxiliary that appears in children’s spontaneous
speech is essere (= to be) which selects unaccusative or defective
predicates, while avere (= to have), which selects a full sentence with an
external argument (namely, transitive predicates), appears later and is not
produced and comprehended in an adult-like way. Our hypothesis is that
the complexity of verbs affects the production and comprehension of
auxiliaries in child Italian. For complexity we refer to the argument
structure projected by each verbal head. The verbs which project internal
arguments (unaccusatives and transitives) are less complex for their
aspectual entailment than the verbs which project only external arguments
(unergatives). The sentences involving auxiliaries are aspectually marked:
the passato prossimo (=present perfect) tensed constructions, in fact, entail
a perfective reading. The aspectual reading of the auxiliary interacts with
the aspectual interpretation of each verb class.
