How to convert words in past tense to past participal form?

Dear student 

Past participles can be formed by adding -ed, -d, -t, -en, or -n to the end of the given verb. However, this usually depends on the verb itself, as regular and irregular verbs have different rules. 

The following words are examples of regular verbs. Here, the past participle is formed by adding -ed or -d

Present      Past            Past participle
work         worked        worked
jump         jumped        jumped
paint         painted        painted


However, here are the past participles of irregular verbs, where there is no fixed rule for forming a past participle

Present      Past            Past participle
arise          arose           arisen
choose      chose           chosen 
know        knew            known


Regards