How do you conjugate irregular verbs that take être in the passé composé (present perfect)?

The perfect tense is used to talk about something that happened in the past. It's an action that is completely finished. Some verbs take the auxillary 'être' to form the perfect tense. Firstly, we need to identify which verbs take 'être'. There is a helpful mnemonic to remember which verbs these are; DR + MRS VANDERTRAMP D = devenir (to become)R = revenir (to come again)M = monter (to climb)R = rentrer (to return home)S = sortir (to exit)V = venir (to come)A = arriver (to arrive)N = naitre (to be born)D = descendre (to descend)E = entrer (to enter)R = retourner (to return something)T = tomber (to fall)R = rester ( to rest)A = aller ( to go ) M = mourir (to die) P = partir ( to depart)
These are the infinitives for all the verbs that take etre ( the form you will find in the dictionary). Now, to conjugate these verbs so we can use them in the past tense, we need to know that the auxillary (the starting bit of the sentence i.e. when you say I am, you are etc) are different to the ones you use when the verbs take avoir. They are:Je suis = I am Tu es = you are Il/elle/on est = he/she/we areNous sommes = we areVous etes = you are (formal or plural)Ils/elles = they are

Here are a few examples of where we can conjugate these verbs so they are in the past tense. e.g. aller - to go je suis allé(e) - I wenttu es allé(e) - you wentil, elle, on est allé(e)- he/she/we wentnous sommes allé(e)s - we went vous êtes allé(e)(s) - you wentils, elles sont allé(e)s - they went
Notice that sometimes you may have to add an additional 'e' or 's' onto the end of the conjugated verb. This to make the verb agree with the sentence that it is being used in. If the person being referred to is a girl, you always need to add on an 'e' to make sure the verb agrees, but this is not required if the person is a boy.e.g. She went to the cinema = elle est allée au cinéma. Similarly, if there is more than one person being referred to , then an 's' is required on the end of the verb.e.g. They went to the cinema = ils sont allés au cinéma.

Here's is an example of an '-ir' verb being conjugated:e.g. devenir je suis devenu(e) - I becametu es devenu(e) - you becameil/elle est devenu(e) - he/she becamenous sommes devenu(e)s - we becamevous êtes devenu(e)(s) - you becameils/elles sont devenu(e)s - they became