Recent work on second language acquisition within the generative framework has pointed out interfaces (syntax-discourse, syntax-semantics, etc.) as a residual domain of vulnerability in L2. Rather than in core syntax, it is at the interface level that the divergence between native and non-native grammars has been shown to be more prominent. In this book the investigation of answering strategies and the focalization of new information subjects, which require access to the syntax-discourse interface, will be pursued. Data is collected through an oral elicitation task on Finnish and Italian, a rather unexplored language pair, in various stages of language development: advanced and intermediate L2 acquisition, L1 under L2 attrition, early bilingualism, child monolingual L1 development.