[Sethomas]

Composite past tense participles in regular -er verbs are pronounced the same as the infinitive, but spelled with an é instead. Unless, of course, their used with a feminine or plural subject and are conjugated with être, in which case they have to show agreement.

Maybe they need agreement even with avoir in certain usages, I don't know because I fucking hate written French over spoken French and it doesn't matter one fucking bit in spoken French.