In this study, the use of the preposition "pour" (for) in Ontario French is analyzed: (1) in its use with the verb "payer" (to pay for), and (2) in its durative meaning. Data come from the written and spoken French of three groups of bilingual Franco-Ontarian students from the ninth and twelfth grade. In the written and spoken usage of these students, "pour" is used significantly differently than for a corresponding group of monolingual French speakers. A detailed analysis of the French prepositions "pour,""durant" (during), "pendant" (while), and the English preposition "for," reveals difficulty in determining whether the non-standard usage of the Franco-Ontarian students is due to interference from English or to an overgeneralization of French usage rules. (Author/CLK)