When do you use the imperfect tense?

The imperfect tense is a past tense that describes how things used to be, what used to happen and is used to give opinions about past events . It describes an ongoing action in the past or something that used to happen. It can be used to describe what was happening when something else took place. Here are some examples:J’écoutais de la musique quand il est arrivé. - I was listening to music when he arrived.Quand j’étais plus jeune, je jouais au tennis chaque samedi. - When I was younger, I used to play tennis every Saturday.