A study is reported of the language behavior of trilingual 9-to-12-year-old native Italian speakers in Montreal, some of whom were studying Italian on Saturdays and some of whom were not. The study focused on their available vocabulary in the three languages (Italian, French, and English) and on their language productivity during their various activities. A comparison was made between this group and monolinguals and bilinguals. The report outlines the sociohistory of the Montreal Italian community, characteristics of the Italian spoken in Montreal, a description of the study, and quantitative and qualitative analyses of the data. The findings are presented and examined in the context of the importance of the home language, the comparable vocabulary of persons in France and Acadia, and the "balance effect theory" of language and the "principle of languages for communication." It is concluded that the conscious study of the home language does not slow the intellectual development of the adolescent; rather, it appears to correlate positively and strongly with academic achievement. (MSE)