The imperfect tense is used to describe what used to happen in the past, how people felt, something you used to do regularly in the past or to indicate what was happening when something else took place. Examples include: J'étais très triste quand elle est partie. (I was very sad when she left). On se réveillait tôt quand on était jeune. (We used to wake up early when we were younger). You use the same stem as for verbs in the perfect tense and then you add the correct ending depending on je- tu- il- nous- vous- ils-.