Past Participles of Irregular Verbs

In many cases, irregular verbs have irregular past participles and can be grouped according to their endings, as shown in Tables 1, 2, 3, and 4.

Irregular verbs that are contained within a larger verb are used as the basis of the past participle:

mettre (put) and mis (put); permettre (permit) and permis (permitted)
ouvrir (open) and ouvert (opened); couvrir (cover) and couvert (covered)