Résumé:
Through this modest work, we try to identify the reasons for the syntactic and semantic
ambiguity found, written in high school Algeria (final year) Arabic-speaking natives in the use of
prepositions in French language. This study as a part of a syntactic perspective and contrastive,
faces the following problems: why learners do not introduce certain prepositions correctly in
their written work? How can we explain this phenomenon by the interference code switching?
How do the prepositions function at the level of high school pupils? To better guide us in our
approach, the following hypothesis is arouse accordingly: the functioning of prepositional French
related to the public refers to that of the source language. That is to say, the ambiguity in use lies
in being unaware of the difference between the two projecting prepositional namely L1 and L2
that the students return to their first language (in all its varieties) in order to find the proper
preposition to use in their writing. This gives rise to several deviations. To verify the validity of this hypothesis, we conduct at the same time a detailed and concise study and surveys of prepositional phrases taken from written productions of our subjects.
