A question which blights both GCSE and A Level students and becomes particularly relevant when doing translation work. The imperfect tense refers to actions that took place over a long period in the past, and it is often used in description. The passé composé is used for singular events which were completed. However in structures where they are used side by side, they give a greater textual narrative; i.e. as something was (imperfect) happening, then something else happened (passé composé ). This easy switch between tenses gives a greater sense of meaning, which needs to be communicated in translation work. This is a problem of both grammar and meaning.