There are two main classes of verbs in English: strong and weak ... There is one verb that is irregular and weak in the past tense, but strong in the the non-progressive participle: do, did, done. A ...

Form the perfect tense using the auxiliary verb 'haber' and a past participle. Irregular verbs in the perfect tense in Spanish The perfect tense is made of the verb 'haber' and a past participle.