Yes, "he climbed" is regular (simple) past tense.
"Climbed" is the past of "climb".
The past tense is climbed.
The simple past tense is climbed.
I had climbed.
Climbed Damaged Drifted Disappeared Dwindled All those verbs are regular, so the take the -ed ending when forming the past tense.
No, it is not a verb. Clime is a noun (a climate).
No, it is not. It is the past tense and past participle of the verb to climb, and might rarely be used as an adjective (e.g. climbed mountains as opposed to unclimbed).
The words "irregular" and "regular" are not verbs and do not have past tense forms.
A noun is a person, place, or thing. Climb or climbed is an action and therefore a verb (past tense verb in the case of climbed).
It might be, rarely, as in climbed mountains versus unclimbed mountains).But it is usually a verb. It is the past tense and past participle of the verb "to climb."
The past tense of "grip" is "gripped." It is used to describe the action of holding something tightly in the past. For example, "She gripped the railing as she climbed the stairs."
The past tense of regular verbs is created by adding -ed. The past tense of irregular verbs doesn't have a pattern like regular verbs and so the past tense must simply be learned.