This paper analyzes spoken usage of English prepositions by two groups of Ontarian elementary students at the Grade 2 and Grade 5 levels. The first group (29 subjects) consists of bilingual Franco-Ontarian students from Welland and Sudbury. The second group (8 subjects) is composed of monolingual English students from Toronto. Examination of the frequency of preposition errors in obligatory contexts reveals: (a) the order of preposition acquisition is essentially the same for the monolingual and bilingual students at both grade levels; (b) the rate of acquisition for the locative prepositions "to" and "into" is lower for the bilinguals than for the monolinguals, although the rate of acquisition for other prepositions is similar for the two groups; and (c) the types of errors found in the bilinguals' preposition usage differ from those found in the monolinguals'. It is argued that points (b) and (c) may indicate influence of French preposition usage, particularly of the prepositions "a" ("at,""to") and "dans" ("in,""into"), on the bilinguals' acquisition of the English locatives "to" and "into." Such interference may thus have a retarding effect on acquisition of certain prepositions in a second language. (Author/CFM)