As in Provenal, the past participle of a large ntimber of verbs of the 2nd and 3rd conjugations is formed, not from the infinitive, but from the perfect (pogut, volgut, tingut suggest the perfects poch, volch, tinch, and not the infinitives poder, voler, tenir).
It is made up of the imperfect subjunctive of the auxiliary verbs followed by the past participle.
For the passive voice, a fi is used, with the past participle of the required verb.
The main part is the ' third part ' of a verb, which is properly called the past participle.
The teacher writes each past participle and each past simple onto separate pieces of paper as they elicit the correct form from the students.