The research reported in this monograph portrays quite an interesting acquisition process with regard to the development of Italian clitics in L2 grammars, and, as such, shed some clearer light on several issues that are still unaccounted for. For instance, although there is a general consensus on their slow development, L2 acquisitionists do not seem to agree on what may cause such a delay and what their initial acquisition stage might be. Are clitic properties entirely (Full Transfer/Full Access Hypothesis: Schwartz and Sprouse 1996), or partially accessed through L1 categories (Missing Surface Inflection Hypothesis: Lardière 1998b), or derived directly from learners’ universal knowledge (Full Access Hypothesis, Epstein et al. 1996)?

Results show that these properties are not totally attained through L1 categories. Learners’ native language grammar does influence the acquisition of these pronouns, but it does not entirely constitute their initial stage. Their acquisition delay may be attributed to several factors, namely (i) a general difficulty to ‘convert’ the syntactic information into appropriate morphological forms, and (ii) the intrinsic complexity of the cliticization process. Furthermore, regarding the issue of accessibility to Universal Grammar in adult age, data seem to justify some form of continuity since clitics, although absent in L1, are fully acquired.