Infinitive is not a verb and does not have any tenses.
infinitive: throw past: threw past participle: thrown ---- infinitive: teach past: taught past participle: taught
infinitive: buy past: bought past participle: bought
experienced?
infinitive: steal past: stole past participle: stolen
The infinitive is to eat; the past tense is ate; the past participle is eaten; the present participle is eating.
infinitive: hatepast: hatedpast participle: hated
infinitive: lendpast: lentpast participle: lent
infinitive: chatpast: chattedpast participle: chatted
infinitive: hurtpast: hurtpast participle: hurt
infinitive: namepast: namedpast participle: named
had is the past tense of have. Have is the infinitive and also may be the present tense, as in I have or we have or they have.
infinitive: take past: took past participle: taken