How do you conjugate irregular verbs in the passé composé

Irregular french verbs take être as their auxiliary, meaning you would replace the avoir component with être in the present tense. 'je vais', for example, would become 'je suis allé' in the perfect tense. Similarly, 'il va' becomes 'il est allé. Irregular verbs must always agree with the subject however (the thing doing the verb) so 'elle reste' in the perfect tense would have to become 'elle est restée' with an additional e to show agreement.Knowledge of the pluperfect i.e. 'i had ran' is not necessary, but would help you to get top grades. In the case of pluperfect irregular verbs, être, as the auxiliary, would be put into the imperfect tense. So, using the example above, 'i had ran' would become 'J'étais allé'