Explain what has to happen when you use être instead of avoir for the formation of the passé composé?
When using être instead of avoir in the formation of the passé composé, several changes need to occur:
1. Agreement with gender and number: The past participle must agree with the subject in gender and number. For example, if the subject is feminine plural, the past participle must be in the feminine plural form. This agreement is not required when using avoir.
2. Reflexive verbs: When a reflexive verb is used, the reflexive pronoun (me, te, se, nous, vous, se) must be included before the auxiliary verb être. The past participle still agrees with the subject in gender and number.
3. Verbs of motion: Certain verbs of motion, such as aller (to go), venir (to come), and partir (to leave), always use être as the auxiliary verb in the passé composé. Again, the past participle must agree with the subject.
4. Auxiliary verb placement: When using être, the past participle is placed after the auxiliary verb. For example, instead of saying "J'ai mangé" (I have eaten), you would say "Je suis allé(e)" (I have gone).
Overall, when using être in the formation of the passé composé, the past participle agrees with the subject in gender and number, reflexive pronouns are included for reflexive verbs, certain verbs of motion always use être, and the past participle is placed after the auxiliary verb.