To start, the past tense of a verb, better known as the 'perfect' tense, describes an event or action taking place at a different time period compared to the imperfect tense. The perfect tense describes a 'one-off action'; something that only took place once, such as 'J'ai mangé un pomme' or 'I ate an apple'.However, the imperfect tense describes an action that took place continuously throughout the past - something which took place over a longer period of time - and no longer occurs. This could be an hobby, for example. 'Je jouais au foot' or 'I used to play football'.