The study investigates the relationship between input, UG (Universal Grammar) parameter values, and the native language in the acquisition of a purely semantic property that is superficially unrelated to its syntactic trigger, The Bare Noun/Proper Name parameter (Longobardi, 1991; 1994; 1996;2001; 2005). On the one hand, English and Italian bare nouns have identical syntactic form and distribution, but differ in available interpretations. On the other hand, proper names display cross-linguistic constant meaning but variable word order. Variation in this respect can be accounted for by a parameter that is set to one value in English and another one in Italian. A bidirectional study of the two properties was conducted. Individual results calculated with the native speaker accuracy as the cut-off point for successful acquisition indicate that parametric restructuring is attested in both learning directions. In the English → Italian direction, the lack of one native interpretation in the target language (a contracting of the grammar) is achieved in the absence of negative evidence, in a Poverty of the Stimulus situation. In both directions, the semantic property is acquired based on input and/or positive evidence for the syntactic side of the parameter.