Here's why:
* Passé Composé is a compound tense in French, meaning it's formed by combining two elements: an auxiliary verb (either "avoir" or "être") and the past participle of the main verb.
* The past participle is the form of the verb that indicates an action has been completed. It usually ends in "-é" (for regular verbs) or has an irregular form.
Example:
* J'ai mangé (I ate) - "Mangé" is the past participle of the verb "manger" (to eat).
* Elle est arrivée (She arrived) - "Arrivée" is the past participle of the verb "arriver" (to arrive).
Key point: The auxiliary verb (avoir/être) changes based on the subject and tense, but the past participle remains the same.