regular: [verb] + -ed (worked, played, lived)
irregular: learnt one by one (seen, gone, written)
The past participle is one of the three forms you learn for each verb: go – went – gone. It comes after have in the present perfect and after be in the passive (made in Italy).
For most verbs, the past participle is the same as the past simple: the verb + -ed.
The spelling rules are the same as for the past simple: live – lived, stop – stopped, study – studied.
Some verbs have a past participle of their own. Learn them in groups.
The past participle of get is got in British English and gotten in American English, except in have got.
Learners often use the past simple form after have.