We use Le Passé Composé in the same case when we use the Simple Past in English : when the action is finished and to express actions that happened at a defenite time in the past. Example: Je l'ai vu hier. ( I saw him yesterday) L'imparfait, or the Past Continuous in English, is used to express an action which is in progress at a specific time in the past. Example: Elle faisait ses exercices hier soir ( She was doing her exercices last night). It's used also to describe in the past. Example: Il pleuvait à torrent ( It was raining heavily ) Good Luck and sorry for my English !

Passé composé is for (a) completed event or action in the past e.g. he fell, we paid and (b) when 'have / has' is used in English e.g. I have seen that film. Have you been to France? He hasn't forgotten Imparfait (a) in English for "was / were ....... ing" e.g. It was raining, We were waiting. (b) an action that was regular, repeated e.g. She always left at 8.00. (c) a situation or state of affairs rather than an action e.g. it was cold "Il faisait froid" (d) when English has "used to ..... " e.g. He used to work as a porter "Il travaillait comme porteur" Un peu compliqué au début! :))