Based on the description of defective verbal forms in stories, we propose an analysis of errors with a didactic aim. The past perfect is a verbal tense that children know well and use spontaneously. Deficient usage in school stories, however, reveals some difficulties when they imagine mentally the succession of the events of a story in the act of writing. Our hypothesis is two-fold : on the one hand the child has difficulties in representing the order of events, on the other he/she has to choose an event which serves as a temporal mark in the story and allows for the use of a past perfect. The study of discourse where the unsuitable form appears, indicates a conflict in the act of writing, i.e. the difficulty of the writer to unify the narrator's point of view.

This study investigates the acquisition of the imparfait by advanced Swedish learners of French. Their use of the imparfait is compared to that of some native speakers in an interview task. The analysis is based on the relationship between Event Time and Reference Time in different values expressed by the imparfait. It is shown that the learners prefer the imparfait for situations where the actual time of the event (Event Time) completely overlaps with the time spoken about (Reference Time). Situations that imply a distance between the two time spans are only expressed in the imparfait by the most advanced learner and by the native speakers. On the basis of this result, an implicational scale for the acquisition of the contextual values of the imparfait at advanced stages is suggested.