A study investigated the extra-curricular use of French and English by 289 anglophone and ethnic minority fifth and sixth grade students in Montreal. The students were divided into three groups: (1) French sector children in regular French classes; (2) French sector children who were recent immigrants and enrolled in a 10-month familiarization program ("accueil"); and (3) English sector children whose instructional time was divided between French (40%) and English (60%). Results of student diaries and a survey indicate that: (1) the first two groups of students used French significantly more often than the immersion students; (2) the first group's students who spoke English spoke French less often than those who did not speak English; (3) within the first group, students from English-speaking countries used French the least frequently and those from Central Europe or the Middle East used French the most frequently; (4) immersion students used English more often than the regular French program students; (5) the majority of ethnic minority students maintained their language of origin; and (6) where the language of origin was not maintained, English was the language most frequently used. The findings are discussed in terms of a number of ethnolinguistic factors and differences between the all-French and immersion programs. (Author/MSE)